Re: Finding application data after install - a solution?

[Gabriel Genellina]

En Tue, 22 Sep 2009 13:47:09 -0300, Wolodja Wentland  
 escribió:

On Tue, Sep 22, 2009 at 07:42 -0700, Aahz wrote:



>I want to:
>
>1. Give administrators the freedom to install the data wherever  
they

>   want
>2. Adhere to the FHS (installing data within modules breaks it)
>3. Be able to find that data again regardless of the installation
>  scheme used
>
>1 and 2 are easily solved... It was just not possible to find the data
>again. The snippet in the original code solves that.



Given your mention of FHS, it sounds like you are focused on Unix-like
systems, in which case why not rely on the standard mechanisms for  
config

files?


I do not intentionally focus on UNIX type systems, but I have grown up
with *nix and I rather follow one scheme than none at all. But the
proposed way works on Windows as well, although the users might find
previously unseen directories like 'PREFIX/share/foo/doc' and the like
on their system.


I think many Windows users would say WTF!? when seeing those directories -  
and send cordial greetings to you, your parents and your whole family :)
Instead of ending with, e.g., a directory like c:\usr\share\foo\doc, your  
program should ask the OS for the special folder CSIDL_COMMON_APPDATA and  
add the foo\doc part. Or any other suitable standard folder. A directory  
like c:\usr\share\foo on Windows is as ridiculous as /Documents\ and\  
Settings/All\ Users/Application\ Data/foo on any unix like system.



As $DATA_PREFIX is only known at build time there was (until now) no
reliable way to find the data if the only information one can get is
$LIB_PREFIX, because these two might be totally unrelated.


You should probably raise this issue at the distutils-sig mailing list:  
http://www.python.org/community/sigs/current/distutils-sig/


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Re: Twisted: 1 thread in the reactor pattern

[jacopo]

On Sep 23, 5:57 pm, exar...@twistedmatrix.com wrote:
> On 06:08 am, jacopo.pe...@gmail.com wrote:
>
> >I am diving into Twisted and Perspective Broker (PB) in particular and
> >I would like to understand more about what happens behind the
> >curtains.
> >Say I have a client and a server on two different machines, the server
> >gets callRemote() 19s in an asynchronous way, these requests are parked
> >in a queue and then served sequentially (not in parallel  13 correct me
> >if I am wrong).
>
> Since, as you point out below, there is only one thread, the remote
> methods can only be invoked one at a time.
>
> However, rather central to the asynchronous operation of Twisted
> libraries and applications, the remote method itself may return before
> the remote call has been completely serviced.  So while only one remote
> method will run at a time, each of the two remote calls may run
> concurrently at some point before they are responded to.
>
> >If everything is implemented in a single thread, how
> >is it possible that while the processor is engaged in the processing
> >triggered by  callRemote() 19s at the same time the reactor is ready to
> >listen/accept new events and put them in a queue? To me it looks like
> >there should be at least 2 processes, one for the reactor and on for
> >the rest.
>
> It isn't possible.  While the remote methods are running, other events
> are not being serviced.  This is what is meant when people describe
> Twisted as a "*cooperative* multitasking" system.  Event handlers (such
> as remote methods) run for a short enough period of time that it doesn't
> matter that the reactor is prevented from accepting new connections (or
> what have you) for the duration of their execution.
>
> Jean-Paul

Jean -Paul, not sure I have understood.
Say I have one server S and two clients C1 and C2 (all on separate
machines).

(a) C1 requests a remote call of f1() to S, f1() requires 5 minutes of
processing.
(b) S  puts f1() in a queue and returns immediately a Deferred to
C1.
(c) Now f1() starts and keeps S’s processor busy for 5 mins
(d)  after few seconds C2 requests a remote call f2() to S.
(e) On S the processor is already engaged with f1() but still
“someone” on S is able to accept the request from C2, put it in a
queue (after f1()) and return a Deferred to C2.
(f) At some point after f1() is finished f2() will start

I believe (b) is what you say “run for a short enough period of time
that it doesn't
matter that the reactor is prevented from accepting new connections
(or
what have you) for the duration of their execution.” ?!

Don’t we have (c) and (e) running at the same time here? How is it
possible to have only one Thread?

Thanks,
 Jacopo
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Re: logging.handlers.SMTPHandler question

[Vinay Sajip]

On Sep 24, 4:14 am, akonsu  wrote:
> hello,
>
> SMTPHAndler seems to email every single record separately. is there a
> way to collect all log output and then send it in a single email
> message? or do i have to do it manually?
>

You can use a buffering SMTP handler, see:

http://gist.github.com/192587

I haven't tested this code - I got it from this page (Polish
language):

http://python.pinger.pl/m/552751/bufferingsmtphandler
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Screencapture of a video

[koranthala]

Hi,
I was trying to capture the video which I was viewing using
Imagegrab module in PIL (windows). But, I found that the video was not
captured at all. A quick googling tells me that it is because the
windows does not have access to the viewing area.
   Is there any way I can capture the video? It will be very helpful.
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Re: logging.handlers.SMTPHandler question

[Vinay Sajip]

On Sep 24, 8:37 am, Vinay Sajip  wrote:
> On Sep 24, 4:14 am, akonsu  wrote:
>
>
> http://python.pinger.pl/m/552751/bufferingsmtphandler

Looking back at it, it looks as if it's adapted from some test code I
wrote back in 2002, see here:

http://opensolaris.org/sc/src/xen-gate/xvm-3.3+xen.hg/tools/python/logging/logging-0.4.9.2/test/log_test11.py

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Average of entries in a list of lists

[Evora]

Hello,

I'm a bit of a newbie to python, so this may very well be a basic question:

I have a list of lists, with around 1000 lists looking like this:
['0.000744', '0.480106', 'B'].

I need the average of the first to entries of all the lists, can anybody
help how me to do this?

Thanks in advance,
Evora
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Re: Average of entries in a list of lists

[Steven D'Aprano]

On Thu, 24 Sep 2009 01:30:10 -0700, Evora wrote:

> Hello,
> 
> I'm a bit of a newbie to python, so this may very well be a basic
> question:
> 
> I have a list of lists, with around 1000 lists looking like this:
> ['0.000744', '0.480106', 'B'].
> 
> I need the average of the first to entries of all the lists, can anybody
> help how me to do this?

This sounds rather like homework, so here are some clues rather than a 
working solution.

Let's start with a simple function to calculate the average of some 
numbers. This is so trivial you should already have this, or something 
like it:


def average(numbers):
return sum(numbers)/float(len(numbers))


The call to float is to avoid a difficulty with division in versions of 
Python before 3.0. If you're using Python 3.0 or 3.1, you can leave it 
out. If you can guarantee that your numbers will already be floats, you 
can leave it out too. Or you can put this line at the top of your program:

from __future__ import division


Now you need another function which extracts all the numbers from your 
list-of-lists and converts them from strings to floats. 

To extract the first N items from a list L, you use:

L[:N]

For example, if you have L = ['0.1', '0.2', 1234, 'C'] and you want the 
first three items, you would say:

L[:3]

and get:

['0.1', '0.2', 1234]


Secondly, if you have a list of numbers in the form of strings:

L = ['0.1', '0.2']

and you want to get a list of actual floats, you can do this:

a, b = L
numbers = [float(a), float(b)]

but probably faster is:

numbers = map(float, L)


Thirdly, if you have a list-of-lists, and you want to combine values 
taken from each sub-list into a single summary list, you can use a 
variation on the following:


list_of_lists = [ [1, 'a', 'b'], [2, 'c', 'd'], [3, 'e', 'f'] ]
summary = []
for sublist in list_of_lists:
# extract the first item
x = sublist[0]
# add it to the end of the summary
summary.append(x)

# summary should now be [1, 2, 3]



Finally, if you find yourself writing something like:

x, y = sublist
L.append(x)
L.append(y)

you can save two lines by doing this:

L.extend(sublist)



Put all those pieces together, make a few minor modifications, and you 
will get a function that extracts the first two items from each sub-list, 
converts them from strings to floats, and consolidates them into a single 
summary list. Then you can pass that summary list to the average 
function, and Bob's your uncle.




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Re: Intercepting binding?

[Steven D'Aprano]

On Wed, 23 Sep 2009 18:10:10 -0700, andrew cooke wrote:

> these are valid points, but in practice the main use (for the restricted
> application i care about) is si,ple variables, and this is an "optional
> extra" to help the user, so it's OK if it only works sometimes.  at the
> moment i'd be happy with any half-baked unreliable solution that is
> transparent...

Speaking as a user (although not of Andrew's domain specific language), 
I'd like to say to developers PLEASE PLEASE PLEASE don't try to "help me" 
with half-baked unreliable solutions that only work sometimes.

There's few things worse than unreliable tools that break just when 
you've come to rely on them.




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Re: custom data warehouse in python vs. out-of-the-box ETL tool

[Tony Schmidt]

@Martin:  Thanks for your great feedback.

So do you think it would be very beneficial for me to start with an
Inman or Kimball book?  Or do you think it would be just leisure
reading and not very practical at best - fill my head with needless
jargon and inflexible dogmas, at worst?

I took a database class in college, understand the basic principals of
normalisation, and have built a few complicated RDBMS schemas from the
ground up.

On Sep 23, 12:28 pm, "Martin P. Hellwig" 
wrote:
> snfctech wrote:
> > @Martin:  I originally thought that there was nothing "magical" about
> > building a datawarehouse, but then I did a little research and
> > received all sorts of feedback about how datawarehouseprojects have
> > notorious failure rates, that datawarehousedesign IS different than
> > normal RDBMS - and then there's the whole thing about data marts vs.
> > warehouses, Kimball vs. Inmon, star schemas, EAV tables, and so on.
> > So I started to think that maybe I needed to get a little better read
> > on the subject.
>
> Yes failure rate for datawarehouseprojects is quite high, so are other
> IT projects without data warehouses.
>
> Datawarehousedesign is not that much different than 'normal' RDBMS,
> you are following the same decisions for example:
> - Do I rather have multiple copies of data than slow or complicated
> access? If yes how do I ensure integrity?
> - How do I do access control on value level?
> - Do I need fail over or load balancing, if yes how much of it can I do
> on the application level?
>
> The thing is if you never have designed a database from a database point
> of view because you used abstractions that hide these ugly details then
> yes, Data warehouses are different than normal RDBMS.
>
> Yes you can make it all sound very complicated by throwing PHB words in
> like meta schema's, dimensional approach, subject orientated, etc.
> I like to see it more like I have a couple of data sources, I want to
> combine them  in a way that I can do neat stuff with it. The 'combine
> them' part is the datawarehousedesign, the 'neat stuff' part are the
> clients that use that datawarehouse. If you wish you can start making
> it more complicated by saying but my data sources are also my clients,
> but that is another step.
>
> I guess you can sum up all this by saying a datawarehouseis a method
> of gathering already existing data and present them in a different way,
> the concept is simple, the details can be complicated if you want/need
> it to be.
>
> --
> MPHhttp://blog.dcuktec.com
> 'If consumed, best digested with added seasoning to own preference.'

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Re: IDE for python similar to visual basic

[Albert van der Horst]

In article ,
Nobody   wrote:
>On Mon, 07 Sep 2009 23:56:17 +, Albert van der Horst wrote:



>>
>> In view of the above this is not quite the correct way to put it.
>>
>> What I resent is that it leads to a non-professional attitude
>> of the graphical part. Programming is over, lets now kludge
>> some screens together. No. The graphics part has to be carefully
>> designed, carefully tested, and carefully "written", even if it
>> is using a graphical tool. So, yes please, *do* create a GUI
>> "programmatically".
>
>My view is that the program should provide functionality without
>unnecessarily dictating the way in which that functionality is used.
>Essentially, it's an issue of "loose coupling".
>
>The interface really should be configurable by the user according to their
>needs. The code doesn't need to *know* the position or dimensions of
>a widget, or its label or colour or spacing, let alone dictate them.
>
>In most cases, the code shouldn't even get to dictate that specific
>widgets even exist. Rather, it should provide actions which can
>be bound to buttons, menu items and/or accelerators as the user chooses.

I don't necessarily disagree. But how does this work in practice?

I have a totally programmable editor (I do, I'm using it right no.)
I'm able to redefine commands to the point that I have no longer a
command to quit the program, and even have no longer a possibility to
define a new key-combination to quit the program. The hacker who wrote
it would say: "don't do that".
Combined with my habit to switch the Caps lock and control keys
and use the editor full-screen, someone else really gets nowhere.

What if I prefer to have the gaz throttle and the clutch pedal of my
car switched. Is that a good idea?

Bottomline, "let the user choose" must not be an excuse for us,
where we are not able to propose a good choice.

(You may read the subject note-eater on my website.)

Groetjes Albert

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Date using input

[flebber]

Sorry to ask a simple question but I am a little confused how to
combine the input function and the date time module.

Simply at the start of the program I want to prompt the user to enter
the date, desirably in the format dd/mm/year.
However I want to make sure that python understands the time format
because first the date will form part of the name of the output file
so dd/mm/year as 1st September 2009, secondly if I have multiple
output files saved in a directory I may need to search later on the
files and contents of files by date range. So can I timestamp the
file?

I know this is a simple question but it eludes me exactly how to do
it.

I have the basics from http://docs.python.org/library/datetime.html

from datetime import date
date = input("type date dd/mm/year: ")
datetime(day,month,year)

# some program blocks

#print to file(name = date) or apphend if it exists

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very weird python bug..

[Sampsa Riikonen]

Dear List,

Maybe someone could help out with this mysterious bug..

starting a python program in a directory named "python", makes
the importation of modules sometimes impossible with cryptic
error messages..

sam...@linux-912g:~> mkdir paska2
sam...@linux-912g:~>
sam...@linux-912g:~> echo "import scipy" > paska2/testi.py
sam...@linux-912g:~>
sam...@linux-912g:~> export PYTHONPATH=
sam...@linux-912g:~>
sam...@linux-912g:~> python paska2/testi.py
sam...@linux-912g:~>
sam...@linux-912g:~> echo "import scipy" > python/testi.py
sam...@linux-912g:~>
sam...@linux-912g:~> python python/testi.py
Traceback (most recent call last):
  File "python/testi.py", line 1, in 
import scipy
  File "/usr/local/lib/python2.6/site-packages/scipy/__init__.py", line 18, in 

from numpy import oldnumeric
  File "/usr/lib/python2.6/site-packages/numpy/oldnumeric/__init__.py", line 
14, in 
from compat import *
  File "/usr/lib/python2.6/site-packages/numpy/oldnumeric/compat.py", line 97, 
in 
import pickle, copy
  File "/usr/lib/python2.6/pickle.py", line 171, in 
class Pickler:
  File "/usr/lib/python2.6/pickle.py", line 250, in Pickler
def put(self, i, pack=struct.pack):
AttributeError: 'module' object has no attribute 'pack'
---

=> If I start the program in directory "paska2", everythings OK, but if the
directory name happens to be "python", the importation of the modules goes 
nuts!

Very Weird.

Kind Regards,

Sampsa

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Re: Creating a local variable scope.

[Albert van der Horst]

In article <65e8a017-abcb-49ad-8867-bc473f83e...@s39g2000yqj.googlegroups.com>,
Bearophile   wrote:
>Steven D'Aprano:
>
>> (3) Create an inner function, then call that.
>
>Several people after someone gives this anwer.
>
>
>> My personal opinion is that if you really need a local scope
>> inside a function, the function is doing too much and should be split up.
>
>I agree. And a way to split a function is to define an inner function,
>that's one of their main purposes. No need to add other things to the
>language as the OP suggests.

There are exceptions. E.g. implementations of quicksort have a
recursive inner function, that you may prefer to not have exposed.
Also there may be data to communicate to or between instances of
the inner function.

At least that is the situation in most languages. I would be
interested to learn if and how Python gets around that.

>
>Bye,
>bearophile

Groetjes Albert

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Average of entries in a list of lists

[Evora]

Hello,

I'm a bit of a newbie to python, so this may very well be a basic question:

I have a list of lists, with around 1000 lists looking like this:
['0.000744', '0.480106', 'B'].

I need the average of the first to entries of all the lists, can anybody
help how me to do this?

Thanks in advance,
Evora
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Re: easy question, how to double a variable

[Iain King]

On Sep 23, 7:36 pm, David C Ullrich  wrote:
> On Tue, 22 Sep 2009 02:34:53 +, Steven D'Aprano wrote:
> > On Mon, 21 Sep 2009 13:50:23 -0500, David C Ullrich wrote:
>
> >> But you actually want to return twice the value. I don't see how to do
> >> that.
>
> > What?
>
> > Seriously?
>
> You're saying it _can_ be done in Python? They must have added
> something to the standard library again. I mean how can you return
> twice a value without a twice function to start with? I've tried.
> You'd think
>
> def twice(n):
>   return twice(n)
>
> would work, but I get this really long error message.
>
> > You're not just yanking the OP's chain???
>
> That would be cruel. I mean the guy has enough problems already...

Sorry, there is no 'twice' builtin.  I think what you are looking for
is:

def twice(n):
return return n


Iain
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Re: Download and save a picture - urllib

[Piet van Oostrum]

> MRAB  (M) wrote:

>M> mattia wrote:
>>> You were right, the problem was with the print function, using a normal
>>> write everythong works fine.
>>> 
>M> You should open the output file as binary (it doesn't matter on
>M> Linux/Unix, but is a good idea anyway for portability).

It probably DOES matter also on Linux/Unix, as the OP is using Python3.
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Re: very weird python bug..

[Christian Heimes]

Sampsa Riikonen wrote:
> => If I start the program in directory "paska2", everythings OK, but if the
> directory name happens to be "python", the importation of the modules goes 
> nuts!

What's inside the python/ subdirectory? Do you happen to have a file
called struct.py inside it?

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Re: custom data warehouse in python vs. out-of-the-box ETL tool

[M.-A. Lemburg]

snfctech wrote:
> @Lemburg: Thanks for the suggestion.  I'm sure you make a fine
> product, but my development platform is Linux, and I don't want any
> additional Windows servers to deal with (than the ones I'm already
> stuck with.)

Strange, EasySoft used to support their product on Linux as well...

http://download.freshmeat.net/projects/easysoftsqlengine

Looks like they stopped with supporting it on Linux and now only
have Windows downloads available.

mxODBC and mxODBC Connect work just fine on Linux, so you could use
them to build a custom joining solution in Python.

It really depends on whether you need to run those joins on
an on-demand basis or not:

AFAIK, Talend can only run jobs which
then apply the JOINs and put the resulting data somewhere, e.g.
into a file or another database table.

With Python, you could do the join straight away and use the
data directly without the Python script - without having
to go through an external temporary resource.

Anyway, just a suggestion.

> On Sep 23, 2:02 am, "M.-A. Lemburg"  wrote:
>> snfctech wrote:
>>> Does anyone have experience building a data warehouse in python?  Any
>>> thoughts on custom vs using an out-of-the-box product like Talend or
>>> Informatica?
>>
>>> I have an integrated system Dashboard project that I was going to
>>> build using cross-vendor joins on existing DBs, but I keep hearing
>>> that a data warehouse is the way to go.  e.g. I want to create orders
>>> and order_items with relations to members (MS Access DB), products
>>> (flat file) and employees (MySQL).
>>
>>> Thanks in advance for any tips.
>>
>> You might want to look at this solution for doing cross-database JOINs:
>>
>> EasySoft ODBC Join-Engine:
>>
>>http://www.easysoft.com/products/data_access/odbc_odbc_join_engine/in...
>>
>> and then use our mxODBC to access EasySoft's Engine:
>>
>>http://www.egenix.com/products/python/mxODBC/
>>
>> or mxODBC Connect, if you have a client-server setup:
>>
>>http://www.egenix.com/products/python/mxODBCConnect/
>>
>> Some database engines also allow integrating external ODBC
>> data sources - the external tables then look like normal
>> database tables and can be used in JOINs as well. I know that DB2
>> and Oracle support this kind of setup. You can access those using
>> mxODBC as well.
>>
>> --
>> Marc-Andre Lemburg
>> eGenix.com
>>
>> Professional Python Services directly from the Source  (#1, Sep 23 2009)>>> 
>> Python/Zope Consulting and Support ...http://www.egenix.com/
> mxODBC.Zope.Database.Adapter ...http://zope.egenix.com/
> mxODBC, mxDateTime, mxTextTools ...http://python.egenix.com/
>>
>> 
>>
>> ::: Try our new mxODBC.Connect Python Database Interface for free ! 
>>
>>eGenix.com Software, Skills and Services GmbH  Pastor-Loeh-Str.48
>> D-40764 Langenfeld, Germany. CEO Dipl.-Math. Marc-Andre Lemburg
>>Registered at Amtsgericht Duesseldorf: HRB 46611
>>http://www.egenix.com/company/contact/
> 

-- 
Marc-Andre Lemburg
eGenix.com

Professional Python Services directly from the Source  (#1, Sep 24 2009)
>>> Python/Zope Consulting and Support ...http://www.egenix.com/
>>> mxODBC.Zope.Database.Adapter ... http://zope.egenix.com/
>>> mxODBC, mxDateTime, mxTextTools ...http://python.egenix.com/


::: Try our new mxODBC.Connect Python Database Interface for free ! 


   eGenix.com Software, Skills and Services GmbH  Pastor-Loeh-Str.48
D-40764 Langenfeld, Germany. CEO Dipl.-Math. Marc-Andre Lemburg
   Registered at Amtsgericht Duesseldorf: HRB 46611
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Re: Intercepting binding?

[Carl Banks]

On Sep 23, 5:49 pm, "Rhodri James" 
wrote:
> On Thu, 24 Sep 2009 01:34:35 +0100, andrew cooke  wrote:
>
> > For example, I assume it's possible to somehow access the dictionary
> > for the current block, but I can't see how to do this after
> > assignment.  If I do it in the Foo constructor, for example, "a" will
> > not yet be bound.
>
> I apologise for failing to notice earlier that you know what you're
> talking about.  I blame the hour :-)
>
> I'm not sure you can access the namespace dictionary of the "current
> block" (module?), that's the problem.  Oh, except via locals(), which
> might do exactly what you're after depending.  Excuse me, I'm being
> very dim tonight.


Hmmm.


@contextlib.contextmanager
def capture_changed_bindings():
before = sys._getframe(2).f_locals.copy()
changed = {}
yield changed
after = sys._getframe(2).f_locals
for key,value in after.iteritems():
if value is changed:
continue
if key not in before or value is not before[key]:
changed[key] = value

def test():
a = 2
b = 3
c = 4
with capture_changed_bindings() as changed:
b = 5
c = 4
d = 6
print changed

test()


Quick and dirty, not robust at all.  But you get the idea.

Carl Banks
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Re: Average of entries in a list of lists

[Xavier Ho]

On Thu, Sep 24, 2009 at 8:54 PM, Evora  wrote:

>
> Hello,
>
> I'm a bit of a newbie to python, so this may very well be a basic question:
>
> I have a list of lists, with around 1000 lists looking like this:
> ['0.000744', '0.480106', 'B'].
>
> I need the average of the first to entries of all the lists, can anybody
> help how me to do this?
>

Say if we have:

data = [['1', '2', 'B'],
['2', '3', 'B'],
['3', '4', 'B']]

The easier way is to iterate through the big list, and get out the first
item and add them. Once you've added them all, divide by the number of lists
in the big list.

total = 0
for list in data:
total += int(list[0])
print(total/len(data))

# OUTPUT
2.0

Or there is some ... not so obvious way, but same idea:

print(sum(int(numbers[0]) for numbers in data) / len(data))

# OUTPUT
2.0

(I'm using Python 3.1 by the way. You might have to change the print
function.)

Cheers,
Xav
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Re: Finding application data after install - a solution?

[Wolodja Wentland]

On Thu, Sep 24, 2009 at 04:07 -0300, Gabriel Genellina wrote:
> >I do not intentionally focus on UNIX type systems, but I have grown up
> >with *nix and I rather follow one scheme than none at all. But the
> >proposed way works on Windows as well, although the users might find
> >previously unseen directories like 'PREFIX/share/foo/doc' and the like
> >on their system.

> I think many Windows users would say WTF!? when seeing those
> directories - and send cordial greetings to you, your parents and
> your whole family :)

That is probably true, but Windows has a 'etc' directory
(c:\windows\system32\drivers\etc) which AFAIK contains the hosts file
and/or other goodies from *NIX.

> Instead of ending with, e.g., a directory like c:\usr\share\foo\doc,
> your program should ask the OS for the special folder
> CSIDL_COMMON_APPDATA and add the foo\doc part. Or any other suitable
> standard folder. 

Is CSIDL_COMMON_APPDATA and environment variable set on all Windows
flavours? Are there versions that relying on this env var (if it is one)
will cause havoc and the death of millions of kittens? (ie. is it
available on all versions)

Where can I find Information on these "other" standard folders? Sorry,
but I have not used a Windows machine in ages.

> A directory like c:\usr\share\foo on Windows is as ridiculous as
> /Documents\ and\ Settings/All\ Users/Application\ Data/foo on any unix
> like system.

Agreed! Although I find the *NIX flavour more palatable to my eye ;-)

> >As $DATA_PREFIX is only known at build time there was (until now) no
> >reliable way to find the data if the only information one can get is
> >$LIB_PREFIX, because these two might be totally unrelated.
> 
> You should probably raise this issue at the distutils-sig mailing
> list: http://www.python.org/community/sigs/current/distutils-sig/

I already did [1] but the distutils developers are quite busy discussing
a the new format for setup.cfg. I did not got any feedback on the
solution I developed and thought that other Python users might have a
better solution to this problem.

How do *you* deal with application data in your programs? Is there a way
that works on as many platforms as possible?

so long

Wolodja

[1] http://mail.python.org/pipermail/distutils-sig/2009-September/013238.html


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Re: Intercepting binding?

[Carl Banks]

On Sep 23, 7:41 pm, andrew cooke  wrote:
> On Sep 23, 10:11 pm, Dave Angel  wrote:
>
> > This comes up periodically in this list, and the answer is always
> > something like:  you can't get there from here.
>
> Well, I'm both flexible and desperate, so this is a possible route
> (perhaps near enough):
>
> import sys
>
> class Foo(object):
>
>     def __rlshift__(self, name):
>         try:
>             raise Exception()
>         except:
>             locals = sys.exc_traceback.tb_frame.f_back.f_locals
>             locals[name] = self
>
> if __name__ == '__main__':
>     foo = Foo()
>     'a' << foo
>     print(a)

Did you try this inside a function?   (Hint: it won't work in a
function.)

BTW, if you are desperate to do this then I'd say you lack good
perspective.  You are subverting some of the most basic behavior of
Python here for something of marginal and only occasional usefulness.
If you are that desperate just retype the name, it won't be the end of
the world.

a = Foo('a')


Carl Banks
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Re: Finding application data after install - a solution?

[Tim Golden]

Wolodja Wentland wrote:

I think many Windows users would say WTF!? when seeing those
directories - and send cordial greetings to you, your parents and
your whole family :)


That is probably true, but Windows has a 'etc' directory
(c:\windows\system32\drivers\etc) which AFAIK contains the hosts file
and/or other goodies from *NIX.


True, but it's little known and -- as you show -- buried deep in the
innards. I assume that it's the residue (or a symptom) of the Posix
compatibility layer.


Is CSIDL_COMMON_APPDATA and environment variable set on all Windows
flavours? 


Certainly all those which Python currently supports. There are
some small subtleties which have changed between older and
newer versions.

Are there versions that relying on this env var (if it is one)

will cause havoc and the death of millions of kittens? (ie. is it
available on all versions)

Where can I find Information on these "other" standard folders? Sorry,
but I have not used a Windows machine in ages.


(drops CSIDL_COMMON_APPDATA into Google and...)

http://msdn.microsoft.com/en-us/library/bb762494%28VS.85%29.aspx



A directory like c:\usr\share\foo on Windows is as ridiculous as
/Documents\ and\ Settings/All\ Users/Application\ Data/foo on any unix
like system.


Agreed! Although I find the *NIX flavour more palatable to my eye ;-)


And they say familiarity breeds contempt! ;)

TJG
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Re: Intercepting binding?

[andrew cooke]

On Sep 24, 7:12 am, Carl Banks  wrote:
>     with capture_changed_bindings() as changed:
>         b = 5
>         c = 4
>         d = 6
>     print changed
>
> test()
>
> Quick and dirty, not robust at all.  But you get the idea.
>
> Carl Banks

brilliant.  using the with context is an excellent idea.  thanks very
much.

andrew
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Re: Date using input

[Dave Angel]

flebber wrote:

Sorry to ask a simple question but I am a little confused how to
combine the input function and the date time module.

Simply at the start of the program I want to prompt the user to enter
the date, desirably in the format dd/mm/year.
However I want to make sure that python understands the time format
because first the date will form part of the name of the output file
so dd/mm/year as 1st September 2009, secondly if I have multiple
output files saved in a directory I may need to search later on the
files and contents of files by date range. So can I timestamp the
file?

I know this is a simple question but it eludes me exactly how to do
it.

I have the basics from http://docs.python.org/library/datetime.html

from datetime import date
date = input("type date dd/mm/year: ")
datetime(day,month,year)

# some program blocks

#print to file(name = date) or apphend if it exists


  
What version of python is your class, instructor, and text book using?  
If you want to learn fastest, you probably need to be using the same, or 
nearly same environment.  The input() function is one place where it 
matters whether it's Python 2.x or Python 3.x.  While you're at it, you 
should give the rest of your environment, such as which OS.


The doc page you pointed us to is for Python 2.6.2, but the input 
function on that version returns an integer.  Perhaps you want raw_input() ?


What code have you written, and what about it doesn't work?  Have you 
added print statements before the line that causes the error to see what 
the intermediate values are?



To try to anticipate some of your problems, you should realize that in 
most file systems, the slash is a reserved character, so you can't write 
the date that way.  I'd suggest using dashes. I put dates in directory 
names, and I always put year, then month, then day, because then sorting 
the filenames also sorts the dates.  I'm not in a country that sorts 
dates that way, but it does make things easier.  So directories for the 
last few days would be:

2009-09-22
2009-09-23
2009-09-24

When asking the user for a date, or telling him a date, by all means use 
your country's preferred format, as you say.


You mention timestamping the file.  While that can be done (Unix touch, 
for example), I consider it a last resort for keeping track of useful 
information.  At best, it should be an extra "reminder" of something 
that's already in the file contents.  And since many programs make the 
assumption that if the timestamp doesn't change, the contents haven't 
changed, you can only reasonably do this on a file whose contents are 
fixed when first created.


If you control the internal format of the file, put the date there, 
perhaps right after the header which defines the data type and version.



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Re: Average of entries in a list of lists

[Dave Angel]

Evora wrote:

Hello,

I'm a bit of a newbie to python, so this may very well be a basic question:

I have a list of lists, with around 1000 lists looking like this:
['0.000744', '0.480106', 'B'].

I need the average of the first to entries of all the lists, can anybody
help how me to do this?

Thanks in advance,
Evora
  
"first to entries" probably is intended to be "first two entries"  This 
is the same typo you made when you cross-posted on python-tutor.


Have you made a sample program (script) that partially works?  Show us 
what you've done, and explain what's wrong with it.  Usually by that 
time, you'll figure it out yourself, and learn more.  But if you're 
really stuck, and not just wanting someone else to do tonight's 
homework, show us what you've got.


Start with a program that defines a list of maybe 4 lists (you can 
change it to 1000 later).  Just enough data that you can see the 
algorithm working.  Then write some form of loop that you think might 
accomplish the result, or at least a subset of the result.  Show us that 
code, and its output, and explain why it falls short.


And of course, tell us the Python version and OS environment you're 
running in.  You'd be surprised how often that matters.


DaveA

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Re: Re: Date using input

[flebber . crue]

I am using python 2.6.2, I haven't updated to 3.0 yet. No I have no class  
or instructor, I am learning this myself. I have Hetlands book "Beginning  
Python Novice to Professional and online documentation books so Dive into  
Python, python.org etc.


Using the SPE editor.

I have currently only fully written basic psuedocode to give me a basic  
framework to guide myself.


#Basic pseudocode
#Purpose to get raw input and calculate a score for a field of options and  
return that

#score in a set in descending order.
#Multiple sets sould be written to the doc

#Obtain date
#Check if txt file with same date exists. If yes apphend to results to file.
#Obtain location
#Set Dictionary
#Event number
#Obtain set size
#Prompt first entry
#First Entry Number
#First Entry Name
#Set Blocks to obtain and calculate data
#Block 1 example - Placings Block
#Obtain number of events competed in
#Obtain how many times finished first
#Ensure this value is not greater than Number of Events
#Number of Firsts divide by Events * total by 15.
#Obtain Second finishes
#Ensure this value is not greater than Number of Events
#Number of Seconds divide by Events * total by 10.
#Continue On with this
#Block 2 - Lookup coach Dict and apply value.
#Obtain Surname of Coach
#Lookup Coach File and Match Name and get value.
#Blocks continue gaining and calculating values.
#create txt file named using date
#Sum Values Block1 + Block2 etc
#Print to file event number and field with name number individual Block  
totals and Sum Total

#Arranged in descending Sum Total.
#Prompt are there any more events? Yes return to start
#Apphend all additional events to same day file seperated by blank line.


On Sep 24, 2009 9:59pm, Dave Angel  wrote:

flebber wrote:




Sorry to ask a simple question but I am a little confused how to



combine the input function and the date time module.





Simply at the start of the program I want to prompt the user to enter



the date, desirably in the format dd/mm/year.



However I want to make sure that python understands the time format



because first the date will form part of the name of the output file



so dd/mm/year as 1st September 2009, secondly if I have multiple



output files saved in a directory I may need to search later on the



files and contents of files by date range. So can I timestamp the



file?





I know this is a simple question but it eludes me exactly how to do



it.





I have the basics from http://docs.python.org/library/datetime.html





from datetime import date



date = input("type date dd/mm/year: ")



datetime(day,month,year)





# some program blocks





#print to file(name = date) or apphend if it exists









What version of python is your class, instructor, and text book using? If  
you want to learn fastest, you probably need to be using the same, or  
nearly same environment. The input() function is one place where it  
matters whether it's Python 2.x or Python 3.x. While you're at it, you  
should give the rest of your environment, such as which OS.




The doc page you pointed us to is for Python 2.6.2, but the input  
function on that version returns an integer. Perhaps you want  
raw_input() ?




What code have you written, and what about it doesn't work? Have you  
added print statements before the line that causes the error to see what  
the intermediate values are?






To try to anticipate some of your problems, you should realize that in  
most file systems, the slash is a reserved character, so you can't write  
the date that way. I'd suggest using dashes. I put dates in directory  
names, and I always put year, then month, then day, because then sorting  
the filenames also sorts the dates. I'm not in a country that sorts dates  
that way, but it does make things easier. So directories for the last few  
days would be:



2009-09-22



2009-09-23



2009-09-24




When asking the user for a date, or telling him a date, by all means use  
your country's preferred format, as you say.




You mention timestamping the file. While that can be done (Unix touch,  
for example), I consider it a last resort for keeping track of useful  
information. At best, it should be an extra "reminder" of something  
that's already in the file contents. And since many programs make the  
assumption that if the timestamp doesn't change, the contents haven't  
changed, you can only reasonably do this on a file whose contents are  
fixed when first created.




If you control the internal format of the file, put the date there,  
perhaps right after the header which defines the data type and version.






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Re: Intercepting binding?

[andrew cooke]

On Sep 24, 5:20 am, Steven D'Aprano
 wrote:
> Speaking as a user (although not of Andrew's domain specific language),
> I'd like to say to developers PLEASE PLEASE PLEASE don't try to "help me"
> with half-baked unreliable solutions that only work sometimes.
>
> There's few things worse than unreliable tools that break just when
> you've come to rely on them.

The context is that I am looking at how best to provide debugging
support for a recursive descent parser.  If the actions are pure then
the whole thing is deterministic, so it might be possible to do
something like "buddha" (a declarative debugger for haskell).  I'm
also looking for a paper that was linked to somewhere this last month
or so on one of the popular sites/blogs about debugging prolog (since
the two are closely related - depth first search etc) - I know this is
vague, but if it rings a bell with anyone...  Anyway, doing this in
pure Python makes risks losing the information associated with
variable names.  I was wondering how I might reduce that.

The reason I asked for "unreliable half-baked" solutions is that I am
exploring what might be possible and, in my experience, this group
prefers to lecture me on what they think I should do rather than
answer the damn question.  I was hoping that by explicitly saying that
reliability is not important, people might feel more free to give
"wild" ideas that I could learn from and improve on.

It's significant, depressing, and not at all surprising that every
person who replied to this thread told me, in one way or another, that
was I was asking was wrong or impossible or foolhardy.

If I want your advice on how to write popular tools, you can be sure I
will come and ask you for it.  That is not what I asked for here.

But since we're all passing round unsolicited advice, here's some from
me.

Being an anal retentive will get you a long way in programming.
Dotting the "i"s and crossing the "t"s is 99% of what it's all about.
I agree.  But the last 1% requires a little bit of imagination.  You
should try it one day.

Andrew
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Re: Solved - Python: automate input to MySQL query

[Joe Riopel]

On Wed, Sep 23, 2009 at 4:21 PM, D'Arcy J.M. Cain  wrote:
> In any case, I have a strong philosophical objection to using the same
> name to refer to two different things regardless of any operational
> issues.  The manager.firstname and employee.firstname are not the same
> thing and should have different names to reflect that.

They are in separate tables, that should be enough to reflect the fact
that they're not the same thing.

> A similar issue comes up in the classic situation of the inventory table
> price field and the sale item price field.  They sound like the same
> thing but they are not.  One is the current price in the catalogue and
> the other is the price it was sold for at a particular time.  They need
> different names for that reason.

I am not sure if you're talking about two different tables (inventory
and sale?). If you meant a single table; I would hope you don't have
two columns, with the same name, in a single table. If you were
talking about two different tables, see my above comment.
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Re: Date using input

[Dave Angel]

flebber.c...@gmail.com wrote:
I am using python 2.6.2, I haven't updated to 3.0 yet. No I have no 
class or instructor, I am learning this myself. I have Hetlands book 
"Beginning Python Novice to Professional and online documentation 
books so Dive into Python, python.org etc.


Using the SPE editor.

I have currently only fully written basic psuedocode to give me a 
basic framework to guide myself.


#Basic pseudocode
#Purpose to get raw input and calculate a score for a field of options 
and return that

#score in a set in descending order.
#Multiple sets sould be written to the doc

#Obtain date
#Check if txt file with same date exists. If yes apphend to results to 
file.

#Obtain location
#Set Dictionary
#Event number
#Obtain set size
#Prompt first entry
#First Entry Number
#First Entry Name
#Set Blocks to obtain and calculate data
#Block 1 example - Placings Block
#Obtain number of events competed in
#Obtain how many times finished first
#Ensure this value is not greater than Number of Events
#Number of Firsts divide by Events * total by 15.
#Obtain Second finishes
#Ensure this value is not greater than Number of Events
#Number of Seconds divide by Events * total by 10.
#Continue On with this
#Block 2 - Lookup coach Dict and apply value.
#Obtain Surname of Coach
#Lookup Coach File and Match Name and get value.
#Blocks continue gaining and calculating values.
#create txt file named using date
#Sum Values Block1 + Block2 etc
#Print to file event number and field with name number individual 
Block totals and Sum Total

#Arranged in descending Sum Total.
#Prompt are there any more events? Yes return to start
#Apphend all additional events to same day file seperated by blank line.


How many of these steps have you attempted actually coding?  Seems to me 
your first two steps are just string manipulation, and you only need to 
use the datetime module if you need to validate.  In other words, if the 
user specifies the date as 31/09/2009, you might want to later bounce 
back to him with a complaint that September only has 30 days.



So the first task is to accept input in the form   ab/cd/efgh   and 
produce a string  efgh-cd-ab.log   which you will then create as a text 
file.  And if the file exists, you'll append to it instead of 
overwriting it.   Can you do that much?


Make sure each of these is in a function with a good name, so you can 
later refine the behavior, like adding error checking.  So right now, 
you might code the function without error checking, and later add some 
validation, with error messages and new input query.


DaveA

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Re: Finding application data after install - a solution?

[Wolodja Wentland]

On Thu, Sep 24, 2009 at 12:51 +0100, Tim Golden wrote:
> Wolodja Wentland wrote:
> >Is CSIDL_COMMON_APPDATA and environment variable set on all Windows
> >flavours?
> 
> Certainly all those which Python currently supports. There are
> some small subtleties which have changed between older and
> newer versions.

Great!

> >Where can I find Information on these "other" standard folders? Sorry,
> >but I have not used a Windows machine in ages.

> http://msdn.microsoft.com/en-us/library/bb762494%28VS.85%29.aspx

Thank you! I will definitely consider adding better Windows installation
support in one of the next releases.

so long

Wolodja


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Re: Solved - Python: automate input to MySQL query

[Tino Wildenhain]

Hi,

...


code, even that is not needed, as the columns are returned in the order
specified so code /knows/ that the first column is  from /this/
table and the other column with  is from /that/ table).


Unless you get a dictionary return.

In any case, I have a strong philosophical objection to using the same
name to refer to two different things regardless of any operational
issues.  The manager.firstname and employee.firstname are not the same
thing and should have different names to reflect that.


This seems to be a shortcome in your datamodel, in fact I'd see
a firstname of an employee as the same type of information as the
firstname of a manager.

So what you really would have is a table with all the people
and another which declares who is manager of who.

recommended of course is to name different data differently
and also to keep the name of the foreign keys the same on
every table so you can use:

SELECT a,b,c FROM tablea JOIN tableb USING (ab_id)

since this avoids duplicate columns in the result.




A similar issue comes up in the classic situation of the inventory table
price field and the sale item price field.  They sound like the same
thing but they are not.  One is the current price in the catalogue and
the other is the price it was sold for at a particular time.  They need
different names for that reason.


Yes and you should name them different in your query when they appear
in the same result set.

Regards
Tino




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Re: Date using input

[flebber]

On Sep 24, 10:58 pm, Dave Angel  wrote:
> flebber.c...@gmail.com wrote:
> > I am using python 2.6.2, I haven't updated to 3.0 yet. No I have no
> > class or instructor, I am learning this myself. I have Hetlands book
> > "Beginning Python Novice to Professional and online documentation
> > books so Dive into Python, python.org etc.
>
> > Using the SPE editor.
>
> > I have currently only fully written basic psuedocode to give me a
> > basic framework to guide myself.
>
> > #Basic pseudocode
> > #Purpose to get raw input and calculate a score for a field of options
> > and return that
> > #score in a set in descending order.
> > #Multiple sets sould be written to the doc
>
> > #Obtain date
> > #Check if txt file with same date exists. If yes apphend to results to
> > file.
> > #Obtain location
> > #Set Dictionary
> > #Event number
> > #Obtain set size
> > #Prompt first entry
> > #First Entry Number
> > #First Entry Name
> > #Set Blocks to obtain and calculate data
> > #Block 1 example - Placings Block
> > #Obtain number of events competed in
> > #Obtain how many times finished first
> > #Ensure this value is not greater than Number of Events
> > #Number of Firsts divide by Events * total by 15.
> > #Obtain Second finishes
> > #Ensure this value is not greater than Number of Events
> > #Number of Seconds divide by Events * total by 10.
> > #Continue On with this
> > #Block 2 - Lookup coach Dict and apply value.
> > #Obtain Surname of Coach
> > #Lookup Coach File and Match Name and get value.
> > #Blocks continue gaining and calculating values.
> > #create txt file named using date
> > #Sum Values Block1 + Block2 etc
> > #Print to file event number and field with name number individual
> > Block totals and Sum Total
> > #Arranged in descending Sum Total.
> > #Prompt are there any more events? Yes return to start
> > #Apphend all additional events to same day file seperated by blank line.
>
> How many of these steps have you attempted actually coding?  Seems to me
> your first two steps are just string manipulation, and you only need to
> use the datetime module if you need to validate.  In other words, if the
> user specifies the date as 31/09/2009, you might want to later bounce
> back to him with a complaint that September only has 30 days.
>
> So the first task is to accept input in the form   ab/cd/efgh   and
> produce a string  efgh-cd-ab.log   which you will then create as a text
> file.  And if the file exists, you'll append to it instead of
> overwriting it.   Can you do that much?
>
> DaveA

Trying but haven't got it working, thats why I started to try and use
datetime module.
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Re: Finding application data after install - a solution?

[Tim Golden]

Wolodja Wentland wrote:

On Thu, Sep 24, 2009 at 12:51 +0100, Tim Golden wrote:

Wolodja Wentland wrote:

Is CSIDL_COMMON_APPDATA and environment variable set on all Windows
flavours?


Just to clarify, now that I read your post more carefully,
there *is* an environment variable APPDATA which is the
user-specific Application Data (probably what you want).
If you need the common appdata (as in the question above),
this isn't exposed as an env var and you'll need to use
the shell API to query Windows for it.

Be warned: altho' it might appear that there is a common
pattern to these locations, they're not guaranteed, especially
in the face of i18n issues and XP->Vista changes etc.

TJG
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Re: Solved - Python: automate input to MySQL query

[D'Arcy J.M. Cain]

On Thu, 24 Sep 2009 08:49:02 -0400
Joe Riopel  wrote:
> On Wed, Sep 23, 2009 at 4:21 PM, D'Arcy J.M. Cain  wrote:
> > In any case, I have a strong philosophical objection to using the same
> > name to refer to two different things regardless of any operational
> > issues.  The manager.firstname and employee.firstname are not the same
> > thing and should have different names to reflect that.
> 
> They are in separate tables, that should be enough to reflect the fact
> that they're not the same thing.

But manager_id (to join the employee to their manager) is in both tables
and it does refer to the same thing.

> > A similar issue comes up in the classic situation of the inventory table
> > price field and the sale item price field.  They sound like the same
> > thing but they are not.  One is the current price in the catalogue and
> > the other is the price it was sold for at a particular time.  They need
> > different names for that reason.
> 
> I am not sure if you're talking about two different tables (inventory
> and sale?). If you meant a single table; I would hope you don't have
> two columns, with the same name, in a single table. If you were
> talking about two different tables, see my above comment.

I'm talking about two different tables.  Consider an inventory table
that includes the current price of an item.  The invoice line item
table references the inventory table for details of the item.  A
classic mistake is to use the price from the inventory table to
determine the total price (item.quantity * invent.price).  The problem
is that the price may change tomorrow but the price it was sold for
yesterday does not.  Hence, invent.price and item.price are not the
same thing and I would name one of them differently.

-- 
D'Arcy J.M. Cain  |  Democracy is three wolves
http://www.druid.net/darcy/|  and a sheep voting on
+1 416 425 1212 (DoD#0082)(eNTP)   |  what's for dinner.
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Looger object only prints "ERROR"s

[daved170]

hi everybody,
I took your adviced and used the logging object.
I copied the example in 16.6.15.2 - "using logging in multiple
modules" from 
http://docs.activestate.com/activepython/3.1/python/library/logging.html.

unfortunattly it only prints to file the ERROR level's messages and
ignore the others. I tried to change the level with SETLEVEL but it
didn't help.
Any idea? thanks,
DaveD
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Re: easy question, how to double a variable

[Pablo Torres N.]

On Sep 24, 5:51 am, Iain King  wrote:
> On Sep 23, 7:36 pm, David C Ullrich  wrote:
>
>
>
> > On Tue, 22 Sep 2009 02:34:53 +, Steven D'Aprano wrote:
> > > On Mon, 21 Sep 2009 13:50:23 -0500, David C Ullrich wrote:
>
> > >> But you actually want to return twice the value. I don't see how to do
> > >> that.
>
> > > What?
>
> > > Seriously?
>
> > You're saying it _can_ be done in Python? They must have added
> > something to the standard library again. I mean how can you return
> > twice a value without a twice function to start with? I've tried.
> > You'd think
>
> > def twice(n):
> >   return twice(n)
>
> > would work, but I get this really long error message.
>
> > > You're not just yanking the OP's chain???
>
> > That would be cruel. I mean the guy has enough problems already...
>
> Sorry, there is no 'twice' builtin.  I think what you are looking for
> is:
>
> def twice(n):
>     return return n
>
> Iain

Actually, what he wants is:

(def twice (x)
  (+ (once x) (once x)))
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Re: Solved - Python: automate input to MySQL query

[D'Arcy J.M. Cain]

On Thu, 24 Sep 2009 15:03:26 +0200
Tino Wildenhain  wrote:
> > In any case, I have a strong philosophical objection to using the same
> > name to refer to two different things regardless of any operational
> > issues.  The manager.firstname and employee.firstname are not the same
> > thing and should have different names to reflect that.
> 
> This seems to be a shortcome in your datamodel, in fact I'd see
> a firstname of an employee as the same type of information as the
> firstname of a manager.
> 
> So what you really would have is a table with all the people
> and another which declares who is manager of who.

Sure, I was trying to show a hypothetical situation.  In my real
databases I don't do that and in fact I point the manager_id field to
another entry in the same table.  Obviously in that case I am forced to
make it a different name even though it references the same column as
employee_id.

> recommended of course is to name different data differently
> and also to keep the name of the foreign keys the same on
> every table so you can use:
> 
> SELECT a,b,c FROM tablea JOIN tableb USING (ab_id)
> 
> since this avoids duplicate columns in the result.

Exactly.

> > A similar issue comes up in the classic situation of the inventory table
> > price field and the sale item price field.  They sound like the same
> > thing but they are not.  One is the current price in the catalogue and
> > the other is the price it was sold for at a particular time.  They need
> > different names for that reason.
> 
> Yes and you should name them different in your query when they appear
> in the same result set.

I want to name them differently even if they aren't in the same result
set because they are different things that just happen to have the same
type - money.  I wouldn't name every int column "int" and I wouldn't
name every price column "price."

-- 
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http://www.druid.net/darcy/|  and a sheep voting on
+1 416 425 1212 (DoD#0082)(eNTP)   |  what's for dinner.
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Re: Most "active" coroutine library project?

[Antoine Pitrou]

Grant Edwards  invalid.invalid> writes:
> 
> Back when I worked on one of the first hand-held cellular
> mobile phones, it used co-routines where the number of
> coroutines was fixed at 2 (one for each register set in a Z80
> CPU).

Gotta love the lightning-fast EXX instruction. :-)

Regards

Antoine.


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Re: Looger object only prints "ERROR"s

[Jean-Michel Pichavant]

daved170 wrote:

hi everybody,
I took your adviced and used the logging object.
I copied the example in 16.6.15.2 - "using logging in multiple
modules" from 
http://docs.activestate.com/activepython/3.1/python/library/logging.html.

unfortunattly it only prints to file the ERROR level's messages and
ignore the others. I tried to change the level with SETLEVEL but it
didn't help.
Any idea? thanks,
DaveD
  

Diffcult to say without a bunch of code.
I would say that your FileHandler formatter has something wrong.
Please provide the code where you're adding this handler to you logger 
object.
Try to change the format to "%(asctime)s - %(levelname)s - %(message)s" 
for testing purpose and tell us if you still have issues.


/logging/ is the way to go, keep going :o)

Jean-Michel


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Re: Looger object only prints "ERROR"s

[Jean-Michel Pichavant]

Jean-Michel Pichavant wrote:

daved170 wrote:

hi everybody,
I took your adviced and used the logging object.
I copied the example in 16.6.15.2 - "using logging in multiple
modules" from 
http://docs.activestate.com/activepython/3.1/python/library/logging.html. 



unfortunattly it only prints to file the ERROR level's messages and
ignore the others. I tried to change the level with SETLEVEL but it
didn't help.
Any idea? thanks,
DaveD
  

Diffcult to say without a bunch of code.
I would say that your FileHandler formatter has something wrong.
Please provide the code where you're adding this handler to you logger 
object.
Try to change the format to "%(asctime)s - %(levelname)s - 
%(message)s" for testing purpose and tell us if you still have issues.


/logging/ is the way to go, keep going :o)

Jean-Michel



Ignore my post, I just misread your description.
Verify you don't have filters attached to your handlers.
If you have a hierarchy of loggers, make sure their level are all 
correctly set
For instance if you have a 'foo.bar' logger, you may set 'foo.bar' level 
to DEBUG, logs can still be filtered by 'foo' if this logger level is 
still ERROR.


JM
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Regex trouble

[Support Desk]

I am trying to loop over a dictionary  of phone numbers and using a python
regex to determine if they are long distance or local and then adding them
to their appropriate dictionary, My regex doesn't appear to be working
though.
My regex's are these

international__iregex=r'^1?(011|001)'
local__iregex=r'^1?(281|832|713|800)'
#long distance
ld_regex=r'^1?(281|832|713|800|866|877|011|001|888)'

long_distance= {}
My loop:
for key1,value1 in x.items():
if key1 == 'dest':
if re.search(ld_regex,value1):
long_distance[key1] = value1
print long_distance
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Re: Date using input

[flebber]

On Sep 24, 11:10 pm, flebber  wrote:
> On Sep 24, 10:58 pm, Dave Angel  wrote:
>
>
>
> > flebber.c...@gmail.com wrote:
> > > I am using python 2.6.2, I haven't updated to 3.0 yet. No I have no
> > > class or instructor, I am learning this myself. I have Hetlands book
> > > "Beginning Python Novice to Professional and online documentation
> > > books so Dive into Python, python.org etc.
>
> > > Using the SPE editor.
>
> > > I have currently only fully written basic psuedocode to give me a
> > > basic framework to guide myself.
>
> > > #Basic pseudocode
> > > #Purpose to get raw input and calculate a score for a field of options
> > > and return that
> > > #score in a set in descending order.
> > > #Multiple sets sould be written to the doc
>
> > > #Obtain date
> > > #Check if txt file with same date exists. If yes apphend to results to
> > > file.
> > > #Obtain location
> > > #Set Dictionary
> > > #Event number
> > > #Obtain set size
> > > #Prompt first entry
> > > #First Entry Number
> > > #First Entry Name
> > > #Set Blocks to obtain and calculate data
> > > #Block 1 example - Placings Block
> > > #Obtain number of events competed in
> > > #Obtain how many times finished first
> > > #Ensure this value is not greater than Number of Events
> > > #Number of Firsts divide by Events * total by 15.
> > > #Obtain Second finishes
> > > #Ensure this value is not greater than Number of Events
> > > #Number of Seconds divide by Events * total by 10.
> > > #Continue On with this
> > > #Block 2 - Lookup coach Dict and apply value.
> > > #Obtain Surname of Coach
> > > #Lookup Coach File and Match Name and get value.
> > > #Blocks continue gaining and calculating values.
> > > #create txt file named using date
> > > #Sum Values Block1 + Block2 etc
> > > #Print to file event number and field with name number individual
> > > Block totals and Sum Total
> > > #Arranged in descending Sum Total.
> > > #Prompt are there any more events? Yes return to start
> > > #Apphend all additional events to same day file seperated by blank line.
>
> > How many of these steps have you attempted actually coding?  Seems to me
> > your first two steps are just string manipulation, and you only need to
> > use the datetime module if you need to validate.  In other words, if the
> > user specifies the date as 31/09/2009, you might want to later bounce
> > back to him with a complaint that September only has 30 days.
>
> > So the first task is to accept input in the form   ab/cd/efgh   and
> > produce a string  efgh-cd-ab.log   which you will then create as a text
> > file.  And if the file exists, you'll append to it instead of
> > overwriting it.   Can you do that much?
>
> > DaveA
>
> Trying but haven't got it working, thats why I started to try and use
> datetime module.

Surely getting it tottally mixed up

from datetime import date
def ObtainDate(params):
  date = raw_input("Type Date dd/mm/year: %2.0r%2.0r/%2.0r%2.0r/%4.0r
%4.0r%4.0r%4.0r")
 print date.datetime(year-month-day)
 #Check if txt file with same date exists. If yes apphend to results
to file.
date.append(datetime

and

def ObtainDate(params):
date = raw_input("Type Date dd/mm/year: ")
date.format = (%4.0s%4.0s%4.0s%4.0s-%2.0s%2.0s-%2.0s)
print date.format


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Regex trouble

[Support Desk]

I am trying to loop over a dictionary  of phone numbers and using a python
regex to determine if they are long distance or local and then adding them
to their appropriate dictionary, My regex doesn't appear to be working
though.

 

My regex's are these

 

international__iregex=r'^1?(011|001)'  #Anything starting with these
prefixes is International

local__iregex=r'^1?(281|832|713|800)' #anything starting with these are
local

#long distance

ld_regex=r'^1?(281|832|713|800|866|877|011|001|888)'  #any number not
starting with these prefixes is long distance

 

long_distance= {}

My loop:

for key1,value1 in x.items():

if key1 == 'dest':   

if not re.search(ld_regex,value1):

long_distance[key1] = value1

print long_distance

 

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Re: Dynamic Form

[victorsubervi]

in line...

On Wed, Sep 23, 2009 at 9:13 PM, BJ Swope  wrote:

> What is your code not doing?
>

see below

>
> Are you winding up with duplicate data in the DB?
>

yes

>
> Is your web browser re-submitting the form with the same data if you
> refresh the screen?
>

yes

>
> Is your web browser pre-filling the fields of the form due to caching?
>

no

If I must use cookies, do I want cookielib/cookiejar, or just Cookie?
TIA.
V

>
> I don't understand what's not working
>
>
> On Wed, Sep 23, 2009 at 12:40 PM, Victor Subervi 
> wrote:
>
>> I've been trying the hidden field, but the problem is that when I set the
>> variable flag, it stays in memory. I would rather just pass a var like I've
>> been trying, but I don't think it's possible. Any ideas? Is a session cookie
>> the only way? Here's more simplified code:
>>
>> #!/usr/bin/python
>>
>> import cgitb; cgitb.enable()
>> import cgi
>> import sys,os
>> sys.path.append(os.getcwd())
>> import MySQLdb
>> import string, re
>>
>> def client():
>>   form = cgi.FieldStorage()
>>   client = string.replace(string.replace(form.getfirst('client', ''), "'",
>> '''), '"', '"')
>>   flag = form.getfirst('flag', '')
>>   print "Content-Type: text/html"
>>   print
>>   print """
>> > http://www.w3.org/TR/xhtml1/DTD/xhtml1-frameset.dtd";>
>> http://www.w3.org/1999/xhtml";>
>> 
>> """
>>   if flag == '':
>> print """
>> 
>> Company Name: > name='client' />
>> 
>> 
>>   
>> 
>> 
>> 
>> """
>>   else:
>> host = 'h'
>> db = 'db'
>> user = 'u'
>> passwd = '1'
>> database = MySQLdb.connect(host, user, passwd, db)
>> cursor = database.cursor()
>> cursor.execute('insert into companies (client);' % (client))
>> cursor.close()
>> print ''
>>
>> client()
>>
>> TIA,
>> V
>>
>>
>> On Tue, Sep 22, 2009 at 1:43 PM, Dennis Lee Bieber > > wrote:
>>
>>> On Tue, 22 Sep 2009 12:50:31 -0400, Victor Subervi
>>>  declaimed the following in
>>> gmane.comp.python.general:
>>>
>>> > Well it's Web stuff, sure, but it's written in python :) The code
>>> follows.
>>> > The problem is that I haven't figured out how to tell the program that
>>> the
>>> > user has entered data and to clear the cache of that data so that it's
>>> not
>>> > re-entered. How do I do that?
>>>
>>>Remember, HTTP is a stateless protocol. EACH submission is
>>> considered a totally new transaction with no memory of the previous
>>> processing.
>>>
>>>Possible solutions...
>>>
>>> *   Use a session cookie that identifies what phase in the multistep
>>> processing you are in...
>>>
>>> *   Use a hidden field in the form that defaults to, say "False",
>>> when
>>> you first display the form, but then gets set to "True" during the first
>>> response process (and is then sent back out with "True" so the second
>>> response takes a different branch).
>>>
>>> --
>>>Wulfraed Dennis Lee Bieber   KD6MOG
>>>wlfr...@ix.netcom.com   
>>> HTTP://wlfraed.home.netcom.com/
>>>
>>> --
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>>>
>>
>>
>> --
>> http://mail.python.org/mailman/listinfo/python-list
>>
>>
>
>
>  --
> To argue that honorable conduct is only required against an honorable enemy
> degrades the Americans who must carry out the orders. -- Charles Krulak,
> Former Commandant of the Marine Corps
>
> We are all slave to our own paradigm. -- Joshua Williams
>
> If the letters PhD appear after a person's name, that person will remain
> outdoors even after it's started raining. -- Jeff Kay
>
>
> --
> http://mail.python.org/mailman/listinfo/python-list
>
>
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Re: Date using input

[Tim Chase]

Surely getting it tottally mixed up

from datetime import date
def ObtainDate(params):
  date = raw_input("Type Date dd/mm/year: %2.0r%2.0r/%2.0r%2.0r/%4.0r
%4.0r%4.0r%4.0r")
 print date.datetime(year-month-day)


By setting "date = raw_input(...)", you mask the datetime.date 
object preventing you from using it in the next "print" line.


Additionally, the "-" aren't used to separate parameters...you 
want commas.  You also haven't split out the year/month/day bits 
to pass to the date.datetime() constructor.  So immediate 
corrections involve:


1) choose a name other than "date" for the value returned from 
raw_input()


2) take that resulting value from step #1 and split it up so you 
have the constituent parts.  This is a wonderful use for tuple 
assignment.


3) After splitting parts up, you still have strings, so you need 
to convert them to numbers.  (for advanced users, I'd use map() 
to do the conversion in step #2)


4) once you have the year, month, and day values as integers, you 
can pass them to the datetime.date constructor (instead of the 
datetime.date.datetime constructor which is a little weird).



 #Check if txt file with same date exists. If yes apphend to results
to file.
date.append(datetime


You'd then want to create a file-name to open, based on the date 
object.  The strftime() method will help you here (see the docs 
on the format string).  Once you have the filename, you'll want 
to open a file with that name, appending to it if it already 
exists (see the docs on the file() object)


-tkc



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Re: logging.handlers.SMTPHandler question

[Vinay Sajip]

On Sep 24, 4:14 am, akonsu  wrote:
> hello,
>
> SMTPHAndler seems to email every single record separately. is there a
> way to collect all log output and then send it in a single email
> message? or do i have to do it manually?
>
> thanks
> konstantin

See also http://pypi.python.org/pypi/mailinglogger
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setting up dynamic descriptors in Python

[brian huggins]

Hello,

I want to set up descriptors at runtine, but it isn't working the way
i would expect.  Does anybody know if this is possible?  Here is an
example:

class Descriptor(object):
def __init__(self, name) :
self.val=0
self.name = name

def __get__(self, obj, objtype):
print 'Retrieving', self.name
return self.val

def __set__(self, obj, val):
print 'Updating' , self.name
self.val = val

class TestDesc (object):
x=Descriptor ("x")
def __init__ (self):
self.y=Descriptor("y")

And Usage:
>>> test=TestDesc()
>>> test.x=0
Updating x
>>> test.x=4
Updating x
>>> test.x
Retrieving x
4
>>> test.y


When i access y, it appears to be a regular object and not a
descriptor type object like x.  Is there a way to make y work the same
as x but setting it up during object creation?

thanks,
brian




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Re: Most "active" coroutine library project?

[Michele Simionato]

On Aug 23, 5:02 pm, Phillip B Oldham  wrote:
> I've been taking a look at the multitude of coroutine libraries
> available for Python, but from the looks of the projects they all seem
> to be rather "quiet". I'd like to pick one up to use on a current
> project but can't deduce which is the most popular/has the largest
> community.
>
> Libraries I looked at include: cogen, weightless, eventlet and
> circuits (which isn't exactly coroutine-based but it's event-driven
> model was intriguing).
>
> Firstly, are there any others I've missed? And what would the
> consensus be on the which has the most active community behind it?

The newest one seems to be diesel, by Simon Willison & Co: 
http://dieselweb.org/lib
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Re: Regex trouble

[MRAB]

Support Desk wrote:
I am trying to loop over a dictionary  of phone numbers and using a 
python regex to determine if they are long distance or local and then 
adding them to their appropriate dictionary, My regex doesn't appear to 
be working though.


My regex's are these

international__iregex=r'^1?(011|001)'
local__iregex=r'^1?(281|832|713|800)'
#long distance
ld_regex=r'^1?(281|832|713|800|866|877|011|001|888)'

long_distance= {}
My loop:
for key1,value1 in x.items():
if key1 == 'dest':   
if re.search(ld_regex,value1):

long_distance[key1] = value1
print long_distance


Define "not working".

BTW, x.items() will give the key/value pairs, but key1 == 'dest' will be
true for only one of the keys, so you're really only looking at
x['dest'].

Please provide a simple though complete example showing the problem,
stating what you expected and what you actually got, including any
tracebacks if an exception occurred.
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Re: IDE for python similar to visual basic

[brian huggins]

> You can also try Eclipse + PyDev. It's not the same as Visual Studio, and I  
> am not sure about the GUI builder, but I think it's what you want.

I really like Eclipse + Pydev.  It is not a GUI builder at all but it
has a nice debugger, code completion and that kind of thing.  And its
free!

Brian
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Re: Dynamic Form

[BJ Swope]

1. Did you try the headers for no-caching of the page?
2. If you wish to avoid dupes in a DB, Primary Keys are the tool to prevent
duplicates.


On Thu, Sep 24, 2009 at 11:01 AM, victorsubervi wrote:

> in line...
>
> On Wed, Sep 23, 2009 at 9:13 PM, BJ Swope  wrote:
>
>> What is your code not doing?
>>
>
> see below
>
>>
>> Are you winding up with duplicate data in the DB?
>>
>
> yes
>
>>
>> Is your web browser re-submitting the form with the same data if you
>> refresh the screen?
>>
>
> yes
>
>>
>> Is your web browser pre-filling the fields of the form due to caching?
>>
>
> no
>
> If I must use cookies, do I want cookielib/cookiejar, or just Cookie?
> TIA.
> V
>
>>
>> I don't understand what's not working
>>
>>
>> On Wed, Sep 23, 2009 at 12:40 PM, Victor Subervi > > wrote:
>>
>>> I've been trying the hidden field, but the problem is that when I set the
>>> variable flag, it stays in memory. I would rather just pass a var like I've
>>> been trying, but I don't think it's possible. Any ideas? Is a session cookie
>>> the only way? Here's more simplified code:
>>>
>>> #!/usr/bin/python
>>>
>>> import cgitb; cgitb.enable()
>>> import cgi
>>> import sys,os
>>> sys.path.append(os.getcwd())
>>> import MySQLdb
>>> import string, re
>>>
>>> def client():
>>>   form = cgi.FieldStorage()
>>>   client = string.replace(string.replace(form.getfirst('client', ''),
>>> "'", '''), '"', '"')
>>>   flag = form.getfirst('flag', '')
>>>   print "Content-Type: text/html"
>>>   print
>>>   print """
>>> >> http://www.w3.org/TR/xhtml1/DTD/xhtml1-frameset.dtd";>
>>> http://www.w3.org/1999/xhtml";>
>>> 
>>> """
>>>   if flag == '':
>>> print """
>>> 
>>> Company Name: >> name='client' />
>>> 
>>> 
>>>   
>>> 
>>> 
>>> 
>>> """
>>>   else:
>>> host = 'h'
>>> db = 'db'
>>> user = 'u'
>>> passwd = '1'
>>> database = MySQLdb.connect(host, user, passwd, db)
>>> cursor = database.cursor()
>>> cursor.execute('insert into companies (client);' % (client))
>>> cursor.close()
>>> print ''
>>>
>>> client()
>>>
>>> TIA,
>>> V
>>>
>>>
>>> On Tue, Sep 22, 2009 at 1:43 PM, Dennis Lee Bieber <
>>> wlfr...@ix.netcom.com> wrote:
>>>
 On Tue, 22 Sep 2009 12:50:31 -0400, Victor Subervi
  declaimed the following in
 gmane.comp.python.general:

 > Well it's Web stuff, sure, but it's written in python :) The code
 follows.
 > The problem is that I haven't figured out how to tell the program that
 the
 > user has entered data and to clear the cache of that data so that it's
 not
 > re-entered. How do I do that?

Remember, HTTP is a stateless protocol. EACH submission is
 considered a totally new transaction with no memory of the previous
 processing.

Possible solutions...

 *   Use a session cookie that identifies what phase in the multistep
 processing you are in...

 *   Use a hidden field in the form that defaults to, say "False",
 when
 you first display the form, but then gets set to "True" during the first
 response process (and is then sent back out with "True" so the second
 response takes a different branch).

 --
Wulfraed Dennis Lee Bieber   KD6MOG
wlfr...@ix.netcom.com   
 HTTP://wlfraed.home.netcom.com/

 --
  http://mail.python.org/mailman/listinfo/python-list

>>>
>>>
>>> --
>>> http://mail.python.org/mailman/listinfo/python-list
>>>
>>>
>>
>>
>>  --
>> To argue that honorable conduct is only required against an honorable
>> enemy degrades the Americans who must carry out the orders. -- Charles
>> Krulak, Former Commandant of the Marine Corps
>>
>> We are all slave to our own paradigm. -- Joshua Williams
>>
>> If the letters PhD appear after a person's name, that person will remain
>> outdoors even after it's started raining. -- Jeff Kay
>>
>>
>> --
>> http://mail.python.org/mailman/listinfo/python-list
>>
>>
>


-- 
To argue that honorable conduct is only required against an honorable enemy
degrades the Americans who must carry out the orders. -- Charles Krulak,
Former Commandant of the Marine Corps

We are all slave to our own paradigm. -- Joshua Williams

If the letters PhD appear after a person's name, that person will remain
outdoors even after it's started raining. -- Jeff Kay
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Re: custom data warehouse in python vs. out-of-the-box ETL tool

[Tony Schmidt]

Hi, Marc-Andre - well, so far you seem to be the only one suggesting
that cross-database joins is the way to go - everyone else has been
telling me to build a warehouse.  I initially was trying to avoid the
warehouse idea to "avoid going through the external temporary
resource", as you say.  But then the situation came up where the data
warehouse would give me another benefit by enabling power users with
tools like OOBase to do their own reporting.  So I started to re-
consider it, and since then, no one has advised the direct approach
with connections/joins on multiple databases.

Have you had much luck circumventing the need for a data warehouse in
this way?

Thanks.

On Sep 24, 4:10 am, "M.-A. Lemburg"  wrote:
> snfctech wrote:
> > @Lemburg: Thanks for the suggestion.  I'm sure you make a fine
> > product, but my development platform is Linux, and I don't want any
> > additional Windows servers to deal with (than the ones I'm already
> > stuck with.)
>
> Strange, EasySoft used to support their product on Linux as well...
>
> http://download.freshmeat.net/projects/easysoftsqlengine
>
> Looks like they stopped with supporting it on Linux and now only
> have Windows downloads available.
>
> mxODBC and mxODBC Connect work just fine on Linux, so you could use
> them to build a custom joining solution in Python.
>
> It really depends on whether you need to run those joins on
> an on-demand basis or not:
>
> AFAIK, Talend can only run jobs which
> then apply the JOINs and put the resulting data somewhere, e.g.
> into a file or another database table.
>
> With Python, you could do the join straight away and use the
> data directly without the Python script - without having
> to go through an external temporary resource.
>
> Anyway, just a suggestion.
>
>
>
> > On Sep 23, 2:02 am, "M.-A. Lemburg"  wrote:
> >> snfctech wrote:
> >>> Does anyone have experience building a datawarehousein python?  Any
> >>> thoughts on custom vs using an out-of-the-box product like Talend or
> >>> Informatica?
>
> >>> I have an integrated system Dashboard project that I was going to
> >>> build using cross-vendor joins on existing DBs, but I keep hearing
> >>> that a datawarehouseis the way to go.  e.g. I want to create orders
> >>> and order_items with relations to members (MS Access DB), products
> >>> (flat file) and employees (MySQL).
>
> >>> Thanks in advance for any tips.
>
> >> You might want to look at this solution for doing cross-database JOINs:
>
> >> EasySoft ODBC Join-Engine:
>
> >>    http://www.easysoft.com/products/data_access/odbc_odbc_join_engine/in...
>
> >> and then use our mxODBC to access EasySoft's Engine:
>
> >>    http://www.egenix.com/products/python/mxODBC/
>
> >> or mxODBC Connect, if you have a client-server setup:
>
> >>    http://www.egenix.com/products/python/mxODBCConnect/
>
> >> Some database engines also allow integrating external ODBC
> >> data sources - the external tables then look like normal
> >> database tables and can be used in JOINs as well. I know that DB2
> >> and Oracle support this kind of setup. You can access those using
> >> mxODBC as well.
>
> >> --
> >> Marc-Andre Lemburg
> >> eGenix.com
>
> >> Professional Python Services directly from the Source  (#1, Sep 23 
> >> 2009)>>> Python/Zope Consulting and Support ...        
> >> http://www.egenix.com/
> > mxODBC.Zope.Database.Adapter ...            http://zope.egenix.com/
> > mxODBC, mxDateTime, mxTextTools ...        http://python.egenix.com/
>
> >> 
>
> >> ::: Try our new mxODBC.Connect Python Database Interface for free ! 
>
> >>    eGenix.com Software, Skills and Services GmbH  Pastor-Loeh-Str.48
> >>     D-40764 Langenfeld, Germany. CEO Dipl.-Math. Marc-Andre Lemburg
> >>            Registered at Amtsgericht Duesseldorf: HRB 46611
> >>                http://www.egenix.com/company/contact/
>
> --
> Marc-Andre Lemburg
> eGenix.com
>
> Professional Python Services directly from the Source  (#1, Sep 24 2009)>>> 
> Python/Zope Consulting and Support ...        http://www.egenix.com/
> >>> mxODBC.Zope.Database.Adapter ...            http://zope.egenix.com/
> >>> mxODBC, mxDateTime, mxTextTools ...        http://python.egenix.com/
>
> 
>
> ::: Try our new mxODBC.Connect Python Database Interface for free ! 
>
>    eGenix.com Software, Skills and Services GmbH  Pastor-Loeh-Str.48
>     D-40764 Langenfeld, Germany. CEO Dipl.-Math. Marc-Andre Lemburg
>            Registered at Amtsgericht Duesseldorf: HRB 46611
>                http://www.egenix.com/company/contact/

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Re: Dynamic Form

[Brian Victor]

victorsubervi wrote:
> On Wed, Sep 23, 2009 at 9:13 PM, BJ Swope  wrote:
>> Is your web browser re-submitting the form with the same data if you
>> refresh the screen?
> yes

I'm surprised no one has mentioned this before, but the standard
approach to this problem is to redirect after a successful POST.  That
way refreshing the browser won't try to re-POST the form.

http://en.wikipedia.org/wiki/Post/Redirect/Get

-- 
Brian

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Re: Twisted: 1 thread in the reactor pattern

[exarkun]

On 07:10 am, jacopo.pe...@gmail.com wrote:

On Sep 23, 5:57�pm, exar...@twistedmatrix.com wrote:
[snip]


It isn't possible. �While the remote methods are running, other events
are not being serviced. �This is what is meant when people describe
Twisted as a "*cooperative* multitasking" system.  Event handlers 
(such
as remote methods) run for a short enough period of time that it 
doesn't
matter that the reactor is prevented from accepting new connections 
(or

what have you) for the duration of their execution.

Jean-Paul


Jean -Paul, not sure I have understood.
Say I have one server S and two clients C1 and C2 (all on separate
machines).

(a) C1 requests a remote call of f1() to S, f1() requires 5 minutes 
of

processing.
(b) S  puts f1() in a queue and returns immediately a Deferred to
C1.
(c) Now f1() starts and keeps S 19s processor busy for 5 mins
(d)  after few seconds C2 requests a remote call f2() to S.
(e) On S the processor is already engaged with f1() but still
1Csomeone 1D on S is able to accept the request from C2, put it in a
queue (after f1()) and return a Deferred to C2.
(f) At some point after f1() is finished f2() will start

I believe (b) is what you say  1Crun for a short enough period of time
that it doesn't
matter that the reactor is prevented from accepting new connections
(or
what have you) for the duration of their execution. 1D ?!


If you have a function that takes 5 minutes to run, then you're blocking 
the reactor thread for 5 minutes and no other events are serviced until 
the function finishes running.


You have to avoid blocking the reactor thread if you want other events 
to continue to be serviced.  There are various strategies for avoiding 
blocking.  Different strategies are appropriate for different kinds of 
blocking code.


Jean-Paul
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Doubley imported module caused devastating bug

[Zac Burns]

Currently it is possible to import a file of one path to more than one
'instance' of a module. One notable example is "import __init__" from
a package. See 
http://stackoverflow.com/questions/436497/python-import-the-containing-package

This recently caused a devastating bug in some of my code. What I have
is support for the Perforce global options as a context for a perforce
module. 
http://www.perforce.com/perforce/doc.072/manuals/cmdref/o.gopts.html#1040647
This way one can call functions that call many perforce command and
have them execute on a different client for example.

So, in module A and module B both imported the Perforce module, but
they turned out not to be the same module. Module A did "with
Perforce.GlobalOptions(client=client): B.function()"

B.function did not receive the new GlobalOptions because of this
problem. As a result important files on the original client were
overwritten (OUCH).

I would like to propose that it be made impossible in the Python
source to import two instances of the same module.

--
Zachary Burns
(407)590-4814
Aim - Zac256FL
Production Engineer (Digital Overlord)
Zindagi Games
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Re: Date using input

[Dave Angel]

flebber wrote:

On Sep 24, 11:10 pm, flebber  wrote:
  

On Sep 24, 10:58 pm, Dave Angel  wrote:





flebber.c...@gmail.com wrote:
  

I am using python 2.6.2, I haven't updated to 3.0 yet. No I have no
class or instructor, I am learning this myself. I have Hetlands book
"Beginning Python Novice to Professional and online documentation
books so Dive into Python, python.org etc.

Using the SPE editor.

I have currently only fully written basic psuedocode to give me a

basic framework to guide myself.

#Basic pseudocode

#Purpose to get raw input and calculate a score for a field of options
and return that
#score in a set in descending order.
#Multiple sets sould be written to the doc

#Obtain date

#Check if txt file with same date exists. If yes apphend to results to
file.
#Obtain location
#Set Dictionary
#Event number
#Obtain set size
#Prompt first entry
#First Entry Number
#First Entry Name
#Set Blocks to obtain and calculate data
#Block 1 example - Placings Block
#Obtain number of events competed in
#Obtain how many times finished first
#Ensure this value is not greater than Number of Events
#Number of Firsts divide by Events * total by 15.
#Obtain Second finishes
#Ensure this value is not greater than Number of Events
#Number of Seconds divide by Events * total by 10.
#Continue On with this
#Block 2 - Lookup coach Dict and apply value.
#Obtain Surname of Coach
#Lookup Coach File and Match Name and get value.
#Blocks continue gaining and calculating values.
#create txt file named using date
#Sum Values Block1 + Block2 etc
#Print to file event number and field with name number individual
Block totals and Sum Total
#Arranged in descending Sum Total.
#Prompt are there any more events? Yes return to start
#Apphend all additional events to same day file seperated by blank line.


How many of these steps have you attempted actually coding?  Seems to me
your first two steps are just string manipulation, and you only need to
use the datetime module if you need to validate.  In other words, if the
user specifies the date as 31/09/2009, you might want to later bounce
back to him with a complaint that September only has 30 days.
  
So the first task is to accept input in the form   ab/cd/efgh   and

produce a string  efgh-cd-ab.log   which you will then create as a text
file.  And if the file exists, you'll append to it instead of
overwriting it.   Can you do that much?
  
DaveA
  

Trying but haven't got it working, thats why I started to try and use
datetime module.



Surely getting it tottally mixed up

from datetime import date
def ObtainDate(params):
  date =aw_input("Type Date dd/mm/year: %2.0r%2.0r/%2.0r%2.0r/%4.0r
%4.0r%4.0r%4.0r")
 print date.datetime(year-month-day)
 #Check if txt file with same date exists. If yes apphend to results
to file.
date.append(datetime

and

def ObtainDate(params):
date =aw_input("Type Date dd/mm/year: ")
date.format =%4.0s%4.0s%4.0s%4.0s-%2.0s%2.0s-%2.0s)
print date.format



  
As Tim says, first thing you want to do is rename that variable.  You've 
defined two symbols with the same name.


Then I'd ask what that %2.0r  stuff is inside the prompt to the user.

Do you understand what kind of data is returned by raw_input() ?  If so, 
look at the available methods of that type, and see if there's one 
called split() that you can use to separate out the multiple parts of 
the user's response.  You want to separate the dd from the mm and from 
the year.


Once you've split the text, then you want to recombine it in a different 
order, and with dashes between the parts.  If I were at your stage of 
experience, I'd not bother with the datetime module at all.  Just see if 
you can rebuild the string you need, assuming the user has entered a 
valid 10-character string.


Later you can go back and figure out the datetime logic.

DaveA
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test_sys failed

[Eno Compton 3]

On a new python 3 installation on a fedora 7 box, I get a test_sys failure.
Here is the console spew. Couldn't find any discussion about this. Suspect I
have fouled up but I don' t know how to proceed. Ideas?

853 test_sys
854 test test_sys failed -- Traceback (most recent call last):
855   File "/home/eno/Python-3.1.1/Lib/test/test_sys.py", line 379, in
test_43581
856 self.assertEqual(sys.__stdout__.encoding,
sys.__stderr__.encoding)
857 AssertionError: 'ascii' != 'UTF-8'
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Re: Regex trouble

[Simon Forman]

On Thu, Sep 24, 2009 at 10:43 AM, Support Desk  wrote:
> I am trying to loop over a dictionary  of phone numbers and using a python
> regex to determine if they are long distance or local and then adding them
> to their appropriate dictionary, My regex doesn't appear to be working
> though.

"doesn't appear to be working" is a useless way to characterize the
problem you're having.

Always tell us what you expected and what you got instead.  Preferably
with the actual traceback if any.

Also, post a /runnable/ code fragment. That way we can try it out for ourselves.


FWIW this problem is too simple (IMHO) for regular expressions.
Simply carve off the first three digits and check against sets of the
prefixes you're interested in:


#any number starting with these prefixes is not long distance
local_prefixes = set(['832', '877', '888', '713', '866', '011', '001',
'281', '800'])

long_distance= {}
for key1, value1 in x.iteritems():
if key1 == 'dest':
if value1[:3] not in local_prefixes:
long_distance[key1] = value1

HTH,
~Simon



>
> My regex's are these
>
>
>
> international__iregex=r'^1?(011|001)'  #Anything starting with these
> prefixes is International
>
> local__iregex=r'^1?(281|832|713|800)' #anything starting with these are
> local
>
> #long distance
>
> ld_regex=r'^1?(281|832|713|800|866|877|011|001|888)'  #any number not
> starting with these prefixes is long distance
>
>
>
> long_distance= {}
>
> My loop:
>
>                 for key1,value1 in x.items():
>
>                         if key1 == 'dest':
>
>                                 if not re.search(ld_regex,value1):
>
>                                         long_distance[key1] = value1
>
>                                 print long_distance

Out of curiosity, why are you printing the whole dict for every "key1
== 'dest'" even when you're not modifying the output dict?

>
>
>
> --
> http://mail.python.org/mailman/listinfo/python-list
>
>
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Re: Python-URL! - weekly Python news and links (Sep 17)

[Cameron Laird]

In article ,
Gabriel Genellina  wrote (but I edited):
.
.
.
>More ways to define an empty function that you ever imagined:
>http://groups.google.com/group/comp.lang.python/t/c9f494b6745c7d74/
.
.
.
Oops; this should have been http://groups.google.com/group/comp.lang.python/browse_thread/thread/eddc376716d
f2029/ >.
My apology, all.
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Re: DBHandler class for logging?

[kj]

In  Vinay 
Sajip  writes:

>See my answer to a question on Stack Overflow, which has the source
>code for a simple handler which writes to a database using the Python
>DB-API 2.0:

>http://stackoverflow.com/questions/935930/creating-a-logging-handler-to-connect-to-oracle/1014450#1014450

>Although the question relates to Oracle, my answer is not so specific.
>It's not production quality code but it should get you started.


Many thanks, to both you and Diez.

kynn
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Re: pycopg2 build problems

[devaru]

On Sep 24, 2:14 am, phi...@semanchuk.com wrote:
> Quoting Wolodja Wentland :
>
>
>
> > On Wed, Sep 23, 2009 at 12:24 -0700, devaru wrote:
> >> I'm trying to install psycopg2 on my system. I followed the
> >> instruction in INSTALL file and gave the command
> >> python setup.py build
> >> running build
> >> running build_py
> >> running build_ext
> >> error: No such file or directory
>
> > I ran into this some days ago. The problem is not related to the
> > distribution you downloaded, but to missing information about PostgreSQL
> > itself.
>
> > IIRC the file in question is "/usr/bin/pg_config". The file is  
> > probably packaged
> > in some lib*-dev package on your distribution.
>
> That's the most common install problem with psycopg2 -- setup.py can't  
> find (or execute) pg_config which it needs to decide how to talk to  
> Postgres. I remember it giving a different (and more descriptive)  
> error but I haven't used psycopg2 recently.
>
> To the OP: if executing pg_config fails from the same command line in  
> which you're running setup.py, then Wolodja is absolutely correct. You  
> need to get pg_config on your path somewhere, or there might be an  
> environment variable you can set to tell setup where to find it if you  
> don't want it in your path.
>
> Good luck
> Philip
>
>
>
> > --- Debian example ---
> > $ apt-file search /usr/bin/pg_config
> > libpq-dev: /usr/bin/pg_config
> > --- snip ---
>
> > thanks for all the fish
>
> >     Wolodja
>
>

Thank you all.

Yes, as Philip and Wolodja have said, we need pg_config in the PATH
variable for psycopg2 to build.
Then I ran into a problem where I had to install the dependency
package python-devel.
Now psycopg2 installed fine.
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PExpect on Windows System Using Cygwin

[Kevin Holleran]

Hello,

I downloaded and installed the pexpect module and wrote a script.  All is
well and good, but the script proved to be pretty useful and now I was asked
to run it as a scheduled task up on a server to run periodically.  I was
intending on simply packaging it up with Py2Exe and moving it to the server
that way.

However, when I went to test it, I received this error

Traceback (most recent call last):
  File "script.py", line 17, in 
import pexpect
  File "lib\site-packages\pexpect.py", line 85, in 
support it. Pexpect is intended for UNIX-like operating systems.""")
ImportError: No module named resource

A critical module was not found. Probably this operating system does not
support it. Pexpect is intended for UNIX-like operating systems.

So now I realize that when I was testing on my system, I run cygwin and so
everything worked fine

Is there a .dll that I can copy with it or anything so that it works without
having to install cygwin on the server that will be hosting this scheduled
task?

Thanks for any help.

Kevin
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When is divmod(a,b)[0] == floor(a/b)-1 ?

[kj]

The docs for divmod include the following:

divmod(a, b)
...For floating point numbers the result is (q, a % b), where q
is usually math.floor(a / b) but may be 1 less than that. ...

I know that floating point math can sometimes produce "unexpected"
results, so the above caveat is not entirely surprising.  Still,
I would find it helpful to see a specific example where
divmod(a, b)[0] is equal to math.floor(a/b)-1.  Does anybody know
one?

Thanks!

kynn 
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Repeated output when logging exceptions

[John Gordon]

I wrote some code to handle and log exceptions in my application.
It works well, but it produces double output for each exception.
How can I fix this?

Here's the pared-down code:

- main.py
import exceptionLogger
import doStuff

exlog = exceptionLogger.exceptionLogger()

stuff = doStuff.doStuff()

try:
stuff.doit()
except Exception,msg:
exlog.logException()


- exceptionLogger.py
import traceback
import logging
import os

class exceptionLogger:
loggingLevel = ""
logger = None

def __init__(self):
self.logger = logging.getLogger("foo")
self.loggingLevel = "DEBUG"
if self.loggingLevel == "DEBUG":
self.logger.setLevel(logging.DEBUG)
handler = logging.FileHandler("error.txt")
format = "%(asctime)s %(levelname)-8s %(message)s"
formatter = logging.Formatter(format)
handler.setFormatter(formatter)
self.logger.addHandler(handler)

def logMsg(self,message):
try:
if self.loggingLevel == "DEBUG":
self.logger.debug(message)
except:
self.stopLogging()

def logException(self):
"""Write an exception traceback to the logfile."""
# save the stack trace to a file and then copy the contents of that
# file to the log.  (traceback.format_exc would allow us to avoid
# using a temporary file, but it is not available in python 2.3)

TMPFILE = os.tmpfile()
traceback.print_exc(None, TMPFILE)
TMPFILE.flush()
self.logMsg(" ** EXCEPTION BEGINS **")
self.logMsgFromFile(TMPFILE)
self.logMsg(" ** EXCEPTION ENDS   **")

TMPFILE.close()

def logMsgFromFile(self,file):
"""Read the contents of a file into a string and log the string."""
file.seek(0)
msg = ""
for line in file:
msg = msg + line
self.logMsg(msg)

def stopLogging(self):
logging.shutdown()

- doStuff.py
import exceptionLogger

class doStuff:

def doit(self):
exlog = exceptionLogger.exceptionLogger()
try:
raise ValueError, "hi there"
except Exception:
exlog.logException()


And here's the contents of error.txt:

- errror.txt
2009-09-24 14:22:23,288 DEBUG ** EXCEPTION BEGINS **
2009-09-24 14:22:23,288 DEBUG ** EXCEPTION BEGINS **
2009-09-24 14:22:23,288 DEBUGTraceback (most recent call last):
  File "/home/gordonj/exception/doStuff.py", line 8, in doit
raise ValueError, "hi there"
ValueError: hi there

2009-09-24 14:22:23,288 DEBUGTraceback (most recent call last):
  File "/home/gordonj/exception/doStuff.py", line 8, in doit
raise ValueError, "hi there"
ValueError: hi there

2009-09-24 14:22:23,288 DEBUG ** EXCEPTION ENDS   **
2009-09-24 14:22:23,288 DEBUG ** EXCEPTION ENDS   **


As you can see, all of the output is doubled.  Header lines, footer lines,
and body text.

Why is this happening?  I suspect it's because I'm declaring two instances
of the exceptionLogger class, which ends up calling logger.addHandler()
twice.  Is that right?

What would be a better way to handle this?

Thanks.

-- 
John Gordon   A is for Amy, who fell down the stairs
gor...@panix.com  B is for Basil, assaulted by bears
-- Edward Gorey, "The Gashlycrumb Tinies"

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Re: Doubley imported module caused devastating bug

[Ethan Furman]

Zac Burns wrote:

Currently it is possible to import a file of one path to more than one
'instance' of a module. One notable example is "import __init__" from
a package. See 
http://stackoverflow.com/questions/436497/python-import-the-containing-package

This recently caused a devastating bug in some of my code. What I have
is support for the Perforce global options as a context for a perforce
module. 
http://www.perforce.com/perforce/doc.072/manuals/cmdref/o.gopts.html#1040647
This way one can call functions that call many perforce command and
have them execute on a different client for example.

So, in module A and module B both imported the Perforce module, but
they turned out not to be the same module. Module A did "with
Perforce.GlobalOptions(client=client): B.function()"

B.function did not receive the new GlobalOptions because of this
problem. As a result important files on the original client were
overwritten (OUCH).

I would like to propose that it be made impossible in the Python
source to import two instances of the same module.

--
Zachary Burns
(407)590-4814
Aim - Zac256FL
Production Engineer (Digital Overlord)
Zindagi Games


I believe that modules are imported only once, and my toy example 
demonstrates that (python 2.5):


test_import.py:
  """testing multiple imports"""
  CONSTANT = 928
  version = (2, 0, 9)
  plug_ins = []
  random_text = 'some text here'
  def set_text(new_text):
  global random_text
  random_text = new_text
  plug_ins.append(new_text)

A.py:
  import test_import
  print test_import.version
  test_import.set_text('hello!')
  print test_import.plug_ins
  print test_import.CONSTANT
  test_import.CONSTANT = 'changed!'

B.py:
  import test_import
  print test_import.version
  test_import.set_text('world!')
  print test_import.plug_ins
  print test_import.CONSTANT

Running...
  In [1]: import A
  (2, 0, 9)
  ['hello!']
  928

  In [2]: import B
  (2, 0, 9)
  ['hello!', 'world!']
  changed!

As you can see, module A made a change to test_import.CONSTANT, and if 
they were different things then B would not have seen it, yet B *did* 
see it.


This makes me wonder if A) Perforce.GlobalOptions isn't actually setting 
module level variables, or B) B.function is using copies of those 
variables that were set when B was originally imported, so is not seeing 
the changes or C) there is yet another wrinkle here that I don't 
know about.  ;-)


~Ethan~
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Evaluate coding and style

[Brown, Rodrick]

I recently started playing with Python about 3 days now (Ex Perl guy) and 
wanted some input on style and structure of what I'm doing before I really 
start picking up some bad habits here is a simple test tool I wrote to validate 
home dirs on my system.

Please evaluate and let me know what could have been done better. Once again 
this is really my first time using python.


$ ./homedir_exists.py root mqm pcap
root successful!
Directory: /var/arpwatch not found!
pcap successful!
mqm successful!


$ cat homedir_exists.py
#!/usr/bin/env python

import sys, os
from re import match

userlist = []
filename = '/etc/passwd'

for user in sys.argv[1:]:
  userlist.append(user)

try:
  fh = open(filename)
except IOError:
  print "No such filename: %s" % (filename)

def checkDir(username):
  data = fh.readlines()
  for line in data:
for user in username:
  if match(user,line):
s = line.split(':')
if not os.path.isdir(s[5]):
  print "Directory: %s not found!" % (s[5])
print s[0] + " successful!"

checkDir(userlist)
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Re: Looger object only prints "ERROR"s

[Vinay Sajip]

On Sep 24, 2:27 pm, daved170  wrote:
> hi everybody,
> I took your adviced and used theloggingobject.
> I copied the example in 16.6.15.2 - "usingloggingin multiple
> modules" 
> fromhttp://docs.activestate.com/activepython/3.1/python/library/logging.html.
>
> unfortunattly it only prints to file the ERROR level's messages and
> ignore the others. I tried to change the level with SETLEVEL but it
> didn't help.
> Any idea? thanks,
> DaveD

You need to post some code. I just copied and pasted that example into
app.py and auxiliary_module.py, and running it produced a spam.log
file with the expected results. So your copy must be different from
that example, and the problem will be somehow related to something
you've changed.

Regards,

Vinay Sajip
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help wanted with list

[Ahmed Shamim]

list = [ 'a', '1', 'b', '2']
what would be the logic, if I input a to get output 1.
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Re: help wanted with list

[Iuri]

You should use a dictionary.
dic = {'a':1, 'b':2}

Use dic['a'] to get output 1.

[]s
iurisilvio



On Thu, Sep 24, 2009 at 5:31 PM, Ahmed Shamim wrote:

> list = [ 'a', '1', 'b', '2']
> what would be the logic, if I input a to get output 1.
> --
> http://mail.python.org/mailman/listinfo/python-list
>
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Re: Doubley imported module caused devastating bug

[Carl Banks]

On Sep 24, 10:26 am, Zac Burns  wrote:
> Currently it is possible to import a file of one path to more than one
> 'instance' of a module. One notable example is "import __init__" from
> a package. 
> Seehttp://stackoverflow.com/questions/436497/python-import-the-containin...
>
> This recently caused a devastating bug in some of my code. What I have
> is support for the Perforce global options as a context for a perforce
> module.http://www.perforce.com/perforce/doc.072/manuals/cmdref/o.gopts.html#...
> This way one can call functions that call many perforce command and
> have them execute on a different client for example.
>
> So, in module A and module B both imported the Perforce module, but
> they turned out not to be the same module. Module A did "with
> Perforce.GlobalOptions(client=client): B.function()"
>
> B.function did not receive the new GlobalOptions because of this
> problem. As a result important files on the original client were
> overwritten (OUCH).
>
> I would like to propose that it be made impossible in the Python
> source to import two instances of the same module.

Impossible's a pretty strong word.

It's a reasonable request, but with Python's importing the way it is
it'd be kind of hard to do.  A Python file can be visible in multiple
ways.

However, anyone who does "import __init__" (or "from . import
__init__" with relative import) is asking for trouble, I can't think
of any valid reason to do it, and I wouldn't mind seeing that
forbidden, but it's simple to avoid.  Someone probably did that
because they didn't know how to import a containing package from one
of its modules, failing to realize that it created a new module.


Carl Banks
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iterate over list while changing it

[Torsten Mohr]

Hello,

a = [1, 2, 3, 4, 5, 6]

for i, x in enumerate(a):
if x == 3:
a.pop(i)
continue

if x == 4:
a.push(88)

print "i", i, "x", x

I'd like to iterate over a list and change that list while iterating.
I'd still like to work on all items in that list, which is not happening
in the example above.
The conditions in the example are not real but much more complex
in reality.

Can anybody tell me how to do this?


Thanks for any hints,
Torsten.


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Re: help wanted with list

[Simon Brunning]

2009/9/24 Ahmed Shamim :
> list = [ 'a', '1', 'b', '2']
> what would be the logic, if I input a to get output 1.

Turn it into a dictionary first:

>>> mylist = [ 'a', '1', 'b', '2']
>>> mydict = dict(zip(mylist[::2], mylist[1::2]))
>>> mydict['a']
'1'

-- 
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Simon B.
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help wanted with list

[Xavier Lapointe]

Not sure I understand well, but let say I did..

list[list.index('a')+1]

Le 14:59, Ahmed Shamim a écrit :

list = [ 'a', '1', 'b', '2']
what would be the logic, if I input a to get output 1.

   


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Re: Doubley imported module caused devastating bug

[Zac Burns]

On Thu, Sep 24, 2009 at 1:38 PM, Carl Banks  wrote:
> On Sep 24, 10:26 am, Zac Burns  wrote:
>> Currently it is possible to import a file of one path to more than one
>> 'instance' of a module. One notable example is "import __init__" from
>> a package. 
>> Seehttp://stackoverflow.com/questions/436497/python-import-the-containin...
>>
>> This recently caused a devastating bug in some of my code. What I have
>> is support for the Perforce global options as a context for a perforce
>> module.http://www.perforce.com/perforce/doc.072/manuals/cmdref/o.gopts.html#...
>> This way one can call functions that call many perforce command and
>> have them execute on a different client for example.
>>
>> So, in module A and module B both imported the Perforce module, but
>> they turned out not to be the same module. Module A did "with
>> Perforce.GlobalOptions(client=client): B.function()"
>>
>> B.function did not receive the new GlobalOptions because of this
>> problem. As a result important files on the original client were
>> overwritten (OUCH).
>>
>> I would like to propose that it be made impossible in the Python
>> source to import two instances of the same module.
>
> Impossible's a pretty strong word.
>
> It's a reasonable request, but with Python's importing the way it is
> it'd be kind of hard to do.  A Python file can be visible in multiple
> ways.
>
> However, anyone who does "import __init__" (or "from . import
> __init__" with relative import) is asking for trouble, I can't think
> of any valid reason to do it, and I wouldn't mind seeing that
> forbidden, but it's simple to avoid.  Someone probably did that
> because they didn't know how to import a containing package from one
> of its modules, failing to realize that it created a new module.
>
>
> Carl Banks
> --
> http://mail.python.org/mailman/listinfo/python-list
>

There are corner cases. The corner case that I ran into was that there
were two ways to find the module on PATH because one value of PATH was
over another. Since then this problem has been removed and it wasn't
too much trouble to work around - but finding the problem was a real
pain.

I am not intimately familiar with the import code and trust your
judgment that it is difficult. If people are in agreement that this
should be changed though it could be put in a list somewhere waiting
for some ambitious person to figure out the implementation, no?

Personally I think it would be worthwhile.

--
Zachary Burns
(407)590-4814
Aim - Zac256FL
Production Engineer (Digital Overlord)
Zindagi Games
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Re: When is divmod(a,b)[0] == floor(a/b)-1 ?

[Robert Kern]

On 2009-09-24 14:40 PM, kj wrote:


The docs for divmod include the following:

 divmod(a, b)
 ...For floating point numbers the result is (q, a % b), where q
 is usually math.floor(a / b) but may be 1 less than that. ...

I know that floating point math can sometimes produce "unexpected"
results, so the above caveat is not entirely surprising.  Still,
I would find it helpful to see a specific example where
divmod(a, b)[0] is equal to math.floor(a/b)-1.  Does anybody know
one?


In [21]: a = 10.0

In [22]: b = 10.0 / 3.0

In [24]: divmod(a, b)[0]
Out[24]: 2.0

In [25]: math.floor(a / b) - 1.0
Out[25]: 2.0

--
Robert Kern

"I have come to believe that the whole world is an enigma, a harmless enigma
 that is made terrible by our own mad attempt to interpret it as though it had
 an underlying truth."
  -- Umberto Eco

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Re: iterate over list while changing it

[Terry Reedy]

Torsten Mohr wrote:

Hello,

a = [1, 2, 3, 4, 5, 6]

for i, x in enumerate(a):


If you change a list while iterating over, start at the tail.

...reversed(enumerate(a))



if x == 3:
a.pop(i)


 del a[i] # you already have the item


continue

if x == 4:
a.push(88)


no such list method, which mean you did not run the above before 
posting. Boo!




print "i", i, "x", x

I'd like to iterate over a list and change that list while iterating.
I'd still like to work on all items in that list, which is not happening
in the example above.
The conditions in the example are not real but much more complex
in reality.

Can anybody tell me how to do this?


Thanks for any hints,
Torsten.




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Re: Evaluate coding and style

[Ethan Furman]

Brown, Rodrick wrote:

I recently started playing with Python about 3 days now (Ex Perl guy) and 
wanted some input on style and structure of what I'm doing before I really 
start picking up some bad habits here is a simple test tool I wrote to validate 
home dirs on my system.

Please evaluate and let me know what could have been done better. Once again 
this is really my first time using python.


All in all it looks pretty good.  Some minor enhancements...




$ ./homedir_exists.py root mqm pcap
root successful!
Directory: /var/arpwatch not found!

  false negative?

pcap successful!
mqm successful!


$ cat homedir_exists.py
#!/usr/bin/env python

import sys, os
from re import match

userlist = []
filename = '/etc/passwd'

for user in sys.argv[1:]:
  userlist.append(user)


since sys.argv is already a list, you can do
  userlist = sys.argv[1:]


try:
  fh = open(filename)
except IOError:
  print "No such filename: %s" % (filename)

def checkDir(username):
  data = fh.readlines()
  for line in data:
for user in username:
  if match(user,line):
s = line.split(':')
if not os.path.isdir(s[5]):
  print "Directory: %s not found!" % (s[5])
print s[0] + " successful!"

checkDir(userlist)


passwd has a well defined layout... instead of using re, I would split 
each line into it's component fields, then just match the username 
fields against the usernames passed in... this also avoids the false 
negative shown in your example, and gets rid of one unnecessary loop.


for line in data:
   fields = line.split(':')
   user = fields[0]
   path = fields[5]
   if user in userlist:
  if os.path.isdir(path):
 print "%s successfull!" % user
  else:
 print "Directory %s for user %s not found!" % (path, user)

Cheers!

~Ethan~
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Re: When is divmod(a,b)[0] == floor(a/b)-1 ?

[kj]

In  Robert Kern 
 writes:

>On 2009-09-24 14:40 PM, kj wrote:
>>
>> The docs for divmod include the following:
>>
>>  divmod(a, b)
>>  ...For floating point numbers the result is (q, a % b), where q
>>  is usually math.floor(a / b) but may be 1 less than that. ...
>>
>> I know that floating point math can sometimes produce "unexpected"
>> results, so the above caveat is not entirely surprising.  Still,
>> I would find it helpful to see a specific example where
>> divmod(a, b)[0] is equal to math.floor(a/b)-1.  Does anybody know
>> one?

>In [21]: a = 10.0

>In [22]: b = 10.0 / 3.0

>In [24]: divmod(a, b)[0]
>Out[24]: 2.0

>In [25]: math.floor(a / b) - 1.0
>Out[25]: 2.0

Wow.  To me this stuff is just black magic, with a bit of voodoo
added for good measure...  Maybe some day I'll understand it.

Thanks!

kynn
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urllib, can't seem to get form post right

[Adam W.]

I'm trying to scrape some historical data from NOAA's website, but I
can't seem to feed it the right form values to get the data out of
it.  Heres the code:

import urllib
import urllib2

## The source page http://www.erh.noaa.gov/bgm/climate/bgm.shtml
url = 'http://www.erh.noaa.gov/bgm/climate/pick.php'
values = {'month' : 'July',
  'year' : '1988'}

user_agent = 'Mozilla/4.0 (compatible; MSIE 5.5; Windows NT)'
headers = { 'User-Agent' : user_agent }

data = urllib.urlencode(values)
req = urllib2.Request(url, data, headers)
response = urllib2.urlopen(req)
the_page = response.read()
print the_page
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Re: Doubley imported module caused devastating bug

[Terry Reedy]

Zac Burns wrote:

On Thu, Sep 24, 2009 at 1:38 PM, Carl Banks  wrote:

On Sep 24, 10:26 am, Zac Burns  wrote:

Currently it is possible to import a file of one path to more than one
'instance' of a module. One notable example is "import __init__" from
a package. 
Seehttp://stackoverflow.com/questions/436497/python-import-the-containin...

This recently caused a devastating bug in some of my code. What I have
is support for the Perforce global options as a context for a perforce
module.http://www.perforce.com/perforce/doc.072/manuals/cmdref/o.gopts.html#...
This way one can call functions that call many perforce command and
have them execute on a different client for example.

So, in module A and module B both imported the Perforce module, but
they turned out not to be the same module. Module A did "with
Perforce.GlobalOptions(client=client): B.function()"

B.function did not receive the new GlobalOptions because of this
problem. As a result important files on the original client were
overwritten (OUCH).

I would like to propose that it be made impossible in the Python
source to import two instances of the same module.

Impossible's a pretty strong word.

It's a reasonable request, but with Python's importing the way it is
it'd be kind of hard to do.  A Python file can be visible in multiple
ways.

However, anyone who does "import __init__" (or "from . import
__init__" with relative import) is asking for trouble, I can't think
of any valid reason to do it, and I wouldn't mind seeing that
forbidden, but it's simple to avoid.


/__init__.py is basically an implementation hack to make a directory 
also 'be' a file. Use at one own risk, I say.




There are corner cases. The corner case that I ran into was that there
were two ways to find the module on PATH because one value of PATH was
over another. Since then this problem has been removed and it wasn't
too much trouble to work around - but finding the problem was a real
pain.

I am not intimately familiar with the import code and trust your
judgment that it is difficult. If people are in agreement that this
should be changed though it could be put in a list somewhere waiting
for some ambitious person to figure out the implementation, no?


1. It would slow down all imports, at least a bit.

2. It would kill code that intentionally makes use of duplicate modules 
(but this could be considered exploitation of a bug, perhaps). It would 
also make forced module reloads harder, it not impossible. Currently, 
just delete the entry in sys.modules.


3. The language itself does not specify how and where from an 
implementation 'initializes' a module on first import. Indeed, CPython 
has at least three options (.py, .zip, and .dll or .pyd (Windows)), with 
hooks for more. Lets a take the request as specifically preventing the 
creation of duplicate module objects from a particular .py file.


One implementatin *might* be add a set to sys, say sys.mod_files for 
x.py or x.pyc files already used to initialize a module. The .py or .pyc 
or .pyo would be stripped but the name otherwise should be the absolute 
path. (Including drive letter, on Windows).


This would not cover the case when files are symlinked (or copied). For 
*nix, a set of inode numbers could be used, but not for Windows.  I 
suspect there might be other system-specific problems I have not thought of.


Terry Jan Reedy

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Re: Evaluate coding and style

[Jon Clements]

On 24 Sep, 21:11, "Brown, Rodrick "  wrote:
> I recently started playing with Python about 3 days now (Ex Perl guy) and 
> wanted some input on style and structure of what I'm doing before I really 
> start picking up some bad habits here is a simple test tool I wrote to 
> validate home dirs on my system.
>
> Please evaluate and let me know what could have been done better. Once again 
> this is really my first time using python.
>
> $ ./homedir_exists.py root mqm pcap
> root successful!
> Directory: /var/arpwatch not found!
> pcap successful!
> mqm successful!
>
> $ cat homedir_exists.py
> #!/usr/bin/env python
>
> import sys, os
> from re import match

Imports are typically one per line. Personally I'd just use import re,
as re.match isn't too much typing and makes it fairly clear to any
Python programmer it's a regex match (as opposed to a filename match
or wildcard match or other such thing)

>
> userlist = []
> filename = '/etc/passwd'

I'd probably have filename as FILENAME as it's almost a constant.

>
> for user in sys.argv[1:]:
>   userlist.append(user)

You don't really need to build userlist like this, try:
userlist = sys.argv[1:]



>
> try:
>   fh = open(filename)
> except IOError:
>   print "No such filename: %s" % (filename)
>

If the file doesn't exist then print it doesn't exist and carry on
regardless anyway? Either re-raise another exception, exit the
program, or don't bother with the try/except and just open the file.
If it doesn't exist, the exception will go unhandled and the program
will stop with the IOError exception.


> def checkDir(username):
>   data = fh.readlines()
>   for line in data:
>     for user in username:
>       if match(user,line):
>         s = line.split(':')
>         if not os.path.isdir(s[5]):
>           print "Directory: %s not found!" % (s[5])
>         print s[0] + " successful!"
>

Conventionally the function would be called checkdir or check_dir. I'd
also pass the file object and userlist as parameters instead of
referring to an outer scope.

You don't need the .readlines, just iterate over the fh object as 'for
line in fh'.

'match' is completely the wrong function to use here. A user of 'r'
will match root, roger, etc... etc... Also, as python supports the in
operator, looping each user is unnecessary, something like:

for line in fh:
tokens = line.split(':')
if tokens[0] in userlist:
if not os.path.isdir(tokens[5]):
print 'Directory %s not found' % tokens[5]
else:
print 'User %s successful' % tokens[0]

> checkDir(userlist)

It's fairly traditional to wrap the 'main' function inside a block to
check if this script is the main one that's executing as such:

if __name__ == '__main__':
checkdir(userlist)

This enables the program to be used in an import so that other
programs can use its functions, but will only execute the check
function, if it's the sole script.


hth a bit,
Jon
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Re: urllib, can't seem to get form post right

[Jon Clements]

On 24 Sep, 22:18, "Adam W."  wrote:
> I'm trying to scrape some historical data from NOAA's website, but I
> can't seem to feed it the right form values to get the data out of
> it.  Heres the code:
>
> import urllib
> import urllib2
>
> ## The source pagehttp://www.erh.noaa.gov/bgm/climate/bgm.shtml
> url = 'http://www.erh.noaa.gov/bgm/climate/pick.php'
> values = {'month' : 'July',
>           'year' : '1988'}
>
> user_agent = 'Mozilla/4.0 (compatible; MSIE 5.5; Windows NT)'
> headers = { 'User-Agent' : user_agent }
>
> data = urllib.urlencode(values)
> req = urllib2.Request(url, data, headers)
> response = urllib2.urlopen(req)
> the_page = response.read()
> print the_page

Hint:

   
 January

 February
 March
 April
 May
 June
 July

 August
 September
 October
 November
 December
   

Jon.
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Re: Evaluate coding and style

[Rhodri James]

On Thu, 24 Sep 2009 21:11:36 +0100, Brown, Rodrick   
 wrote:


I recently started playing with Python about 3 days now (Ex Perl guy)  
and wanted some input on style and structure of what I'm doing before I  
really start picking up some bad habits here is a simple test tool I  
wrote to validate home dirs on my system.


Ethan's made some good points.  Here are a couple more.

[snip]

try:
  fh = open(filename)
except IOError:
  print "No such filename: %s" % (filename)


IOError could be raised for a couple of reasons, not just because the
file doesn't exist, so your printed message is a bit misleading.  Worse,
because you've caught the exception you'll carry on executing, but
with no open file!  checkDir will then complain, and it will all fall
over in one big, misleading mess.

On the whole, it's probably better not bothering with the try...except
since the default behaviour is likely to be what you want anyway.


def checkDir(username):


PEP 8 (the style guide) suggests that function names should be
lowercase_with_underscores.  It's only a suggestion, mind you.


  data = fh.readlines()


Tsk.  Using the fh as a global variable, rather than passing it as
a parameter?  Slapped wrists all round!

In fact the division between what's in the function and what's not
is rather arbitrary at the moment.  I'd be tempted to move the file
opening into the function it would make it a little easier to convert
this script into a module if you ever wanted to.


  for line in data:
for user in username:
  if match(user,line):
s = line.split(':')
if not os.path.isdir(s[5]):
  print "Directory: %s not found!" % (s[5])
print s[0] + " successful!"


Apart from Ethan's fix, there's another issue here.  You don't
catch the case of a username given on the command line not actually
existing in the password file.  That probably means updating the
username list (which is hard if you're iterating over it at the
time) or creating a list of what's been found as you go, and being
aware of the possibility of duplicates.


checkDir(userlist)


If you're going to stuff everything into a function and then
execute it (not a bad idea at all), then there's another idiom
you should know about.

if __name__ == '__main__':
  checkDir(userlist)

(though in reality again you'd think about what you wanted in
checkDir and bung everything else inside the 'if')

The special variable __name__ contains the name of the current
module.  For a script (executing directly from the command line),
the module name is always "__main__".  So when you run
homedir_exists.py from the command line, the condition is true
and your script runs exactly as it does now.

If however you tweak it along the lines I've suggested, you can
use it as a module as well:

-=-=-=-
$ cat trivial_example.py
from homedir_exists import checkDir

# Do something important
checkDir("fred")
# Do something else important
-=-=-=-

In this case, when homedir_exists.py is read in, __name__
will be the name of the module (i.e. "homedir_exists") instead
of "__main__", so the original "checkDir(userlist)" won't be
executed.

--
Rhodri James *-* Wildebeest Herder to the Masses
--
http://mail.python.org/mailman/listinfo/python-list

Re: iterate over list while changing it

[Simon Forman]

On Thu, Sep 24, 2009 at 4:32 PM, Torsten Mohr  wrote:
> Hello,
>
> a = [1, 2, 3, 4, 5, 6]
>
> for i, x in enumerate(a):
>    if x == 3:
>        a.pop(i)
>        continue
>
>    if x == 4:
>        a.push(88)
>
>    print "i", i, "x", x
>
> I'd like to iterate over a list and change that list while iterating.

This is generally a bad idea, but you can do it if you're careful.

Let's check that enumerate() works when you append to the underlying list:

In [1]: n = range(3)

In [2]: for i, x in enumerate(n):
   ...: print i, '=>', x
   ...: if i < 3:
   ...: n.append(23)
   ...:
   ...:
0 => 0
1 => 1
2 => 2
3 => 23
4 => 23
5 => 23

So far so good.  But notice if you delete an item from the list while
iterating over the "enumerate object" the index returned will still be
incremented on the next iteration and you'll skip the item after the
one you just deleted:

In [1]: n = range(3)

In [2]: for i, x in enumerate(n):
   ...: print i, '=>', x, '\t', n
   ...: if i == 1:
   ...: del n[i]
   ...:
   ...:
0 => 0  [0, 1, 2]
1 => 1  [0, 1, 2]

In [3]: n
Out[3]: [0, 2]

In [4]: n = range(6)

In [5]: for i, x in enumerate(n):
   ...: print i, '=>', x, '\t', n
   ...: if i == 3:
   ...: del n[i]
   ...:
   ...:
0 => 0  [0, 1, 2, 3, 4, 5]
1 => 1  [0, 1, 2, 3, 4, 5]
2 => 2  [0, 1, 2, 3, 4, 5]
3 => 3  [0, 1, 2, 3, 4, 5]
4 => 5  [0, 1, 2, 4, 5]



> I'd still like to work on all items in that list, which is not happening
> in the example above.
> The conditions in the example are not real but much more complex
> in reality.
>
> Can anybody tell me how to do this?

You could manage the index yourself, like so:

def f(n):
i = 0
while True:
try:
x = n[i]
except IndexError:
break

print i, '=>', x

if x == 3:
del n[i]
continue

if x == 4:
n.append(23)

# Increment the index
# only if you didn't
# delete anything during
# this iteration.
i += 1


N = range(6)
f(N)
print N


This prints:

0 => 0
1 => 1
2 => 2
3 => 3
3 => 4
4 => 5
5 => 23
[0, 1, 2, 4, 5, 23]


HTH,
~Simon

>
> Thanks for any hints,
> Torsten.
>
>
> --
> http://mail.python.org/mailman/listinfo/python-list
>
-- 
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Re: Intercepting binding?

[Rhodri James]

On Thu, 24 Sep 2009 13:39:57 +0100, andrew cooke  wrote:


On Sep 24, 5:20 am, Steven D'Aprano
 wrote:

Speaking as a user (although not of Andrew's domain specific language),
I'd like to say to developers PLEASE PLEASE PLEASE don't try to "help  
me"

with half-baked unreliable solutions that only work sometimes.

There's few things worse than unreliable tools that break just when
you've come to rely on them.


[snip context]


The reason I asked for "unreliable half-baked" solutions is that I am
exploring what might be possible and, in my experience, this group
prefers to lecture me on what they think I should do rather than
answer the damn question.  I was hoping that by explicitly saying that
reliability is not important, people might feel more free to give
"wild" ideas that I could learn from and improve on.

It's significant, depressing, and not at all surprising that every
person who replied to this thread told me, in one way or another, that
was I was asking was wrong or impossible or foolhardy.


I did apologise.  I'm now going to recant, because (a) you're being
an arse, and (b) I agree 100% with Steven here.  If a tool is going to
break on my when I need it (i.e. in the complicated cases), I don't
bother using that tool again.

--
Rhodri James *-* Wildebeest Herder to the Masses
--
http://mail.python.org/mailman/listinfo/python-list

Re: iterate over list while changing it

[Rhodri James]

On Thu, 24 Sep 2009 21:32:53 +0100, Torsten Mohr  wrote:


Hello,

a = [1, 2, 3, 4, 5, 6]

for i, x in enumerate(a):
if x == 3:
a.pop(i)
continue

if x == 4:
a.push(88)

print "i", i, "x", x

I'd like to iterate over a list and change that list while iterating.
I'd still like to work on all items in that list, which is not happening
in the example above.
The conditions in the example are not real but much more complex
in reality.

Can anybody tell me how to do this?


Generally, don't.  It's much less dangerous to create a new list as you
go.

new_a = []
for x in a:
  if x != 3:
new_a.append(x)
  if x == 4:
new_a.append(88)
# or whatever you intended "push" to mean

If you weren't doing the insertion, you could have used a list
comprehension and neatened things up a bit.

--
Rhodri James *-* Wildebeest Herder to the Masses
--
http://mail.python.org/mailman/listinfo/python-list

Re: Regex trouble

[Rhodri James]

On Thu, 24 Sep 2009 19:45:37 +0100, Simon Forman   
wrote:



FWIW this problem is too simple (IMHO) for regular expressions.
Simply carve off the first three digits and check against sets of the
prefixes you're interested in:


#any number starting with these prefixes is not long distance
local_prefixes = set(['832', '877', '888', '713', '866', '011', '001',
'281', '800'])

long_distance= {}
for key1, value1 in x.iteritems():
if key1 == 'dest':
if value1[:3] not in local_prefixes:
long_distance[key1] = value1


You need to allow for the potential leading 1, which can be done with
a bit of straightforward string slicing but still puts REs more
sensibly in the running.

--
Rhodri James *-* Wildebeest Herder to the Masses
--
http://mail.python.org/mailman/listinfo/python-list

Re: Re: Date using input

[flebber . crue]

Okay, thanks for the advice that sounds a good place to start. I used %2.os  
was an attempt to define width and precision to stop typo errors eg the  
user accidentally inputing 101/09/2009 or similar error. So that the  
__/__/ was adhered to.


I will go back to the start get the basics happening and then figure out a  
way to catch errors with format and correctness.


Thanks


On Sep 25, 2009 3:57am, Dave Angel  wrote:

flebber wrote:




On Sep 24, 11:10 pm, flebber flebber.c...@gmail.com> wrote:






On Sep 24, 10:58 pm, Dave Angel da...@ieee.org> wrote:












flebber.c...@gmail.com wrote:






I am using python 2.6.2, I haven't updated to 3.0 yet. No I have no



class or instructor, I am learning this myself. I have Hetlands book



"Beginning Python Novice to Professional and online documentation



books so Dive into Python, python.org etc.



Using the SPE editor.



I have currently only fully written basic psuedocode to give me a



basic framework to guide myself.



#Basic pseudocode



#Purpose to get raw input and calculate a score for a field of options



and return that



#score in a set in descending order.



#Multiple sets sould be written to the doc



#Obtain date



#Check if txt file with same date exists. If yes apphend to results to



file.



#Obtain location



#Set Dictionary



#Event number



#Obtain set size



#Prompt first entry



#First Entry Number



#First Entry Name



#Set Blocks to obtain and calculate data



#Block 1 example - Placings Block



#Obtain number of events competed in



#Obtain how many times finished first



#Ensure this value is not greater than Number of Events



#Number of Firsts divide by Events * total by 15.



#Obtain Second finishes



#Ensure this value is not greater than Number of Events



#Number of Seconds divide by Events * total by 10.



#Continue On with this



#Block 2 - Lookup coach Dict and apply value.



#Obtain Surname of Coach



#Lookup Coach File and Match Name and get value.



#Blocks continue gaining and calculating values.



#create txt file named using date



#Sum Values Block1 + Block2 etc



#Print to file event number and field with name number individual



Block totals and Sum Total



#Arranged in descending Sum Total.



#Prompt are there any more events? Yes return to start



#Apphend all additional events to same day file seperated by blank line.






How many of these steps have you attempted actually coding? Seems to me



your first two steps are just string manipulation, and you only need to



use the datetime module if you need to validate. In other words, if the



user specifies the date as 31/09/2009, you might want to later bounce



back to him with a complaint that September only has 30 days.



So the first task is to accept input in the form ab/cd/efgh and



produce a string efgh-cd-ab.log which you will then create as a text



file. And if the file exists, you'll append to it instead of



overwriting it. Can you do that much?



DaveA






Trying but haven't got it working, thats why I started to try and use



datetime module.








Surely getting it tottally mixed up





from datetime import date



def ObtainDate(params):



date =aw_input("Type Date dd/mm/year: %2.0r%2.0r/%2.0r%2.0r/%4.0r



%4.0r%4.0r%4.0r")



print date.datetime(year-month-day)



#Check if txt file with same date exists. If yes apphend to results



to file.



date.append(datetime





and





def ObtainDate(params):



date =aw_input("Type Date dd/mm/year: ")



date.format =%4.0s%4.0s%4.0s%4.0s-%2.0s%2.0s-%2.0s)



print date.format











As Tim says, first thing you want to do is rename that variable. You've  
defined two symbols with the same name.





Then I'd ask what that %2.0r stuff is inside the prompt to the user.




Do you understand what kind of data is returned by raw_input() ? If so,  
look at the available methods of that type, and see if there's one called  
split() that you can use to separate out the multiple parts of the user's  
response. You want to separate the dd from the mm and from the year.




Once you've split the text, then you want to recombine it in a different  
order, and with dashes between the parts. If I were at your stage of  
experience, I'd not bother with the datetime module at all. Just see if  
you can rebuild the string you need, assuming the user has entered a  
valid 10-character string.





Later you can go back and figure out the datetime logic.





DaveA


-- 
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Re: Regex trouble

[Simon Forman]

On Thu, Sep 24, 2009 at 6:31 PM, Rhodri James
 wrote:
> On Thu, 24 Sep 2009 19:45:37 +0100, Simon Forman 
> wrote:
>
>> FWIW this problem is too simple (IMHO) for regular expressions.
>> Simply carve off the first three digits and check against sets of the
>> prefixes you're interested in:
>>
>>
>> #any number starting with these prefixes is not long distance
>> local_prefixes = set(['832', '877', '888', '713', '866', '011', '001',
>> '281', '800'])
>>
>> long_distance= {}
>> for key1, value1 in x.iteritems():
>>    if key1 == 'dest':
>>        if value1[:3] not in local_prefixes:
>>            long_distance[key1] = value1
>
> You need to allow for the potential leading 1, which can be done with
> a bit of straightforward string slicing but still puts REs more
> sensibly in the running.
>
> --
> Rhodri James *-* Wildebeest Herder to the Masses
> --
> http://mail.python.org/mailman/listinfo/python-list
>

Wow, I was looking right at it ('1?') and I missed it.  I need more sleep.


This is slightly less win:

for key1, value1 in x.iteritems():
   if key1 == 'dest':
   n = value1[0] == '1'
   if value1[n:n + 3] not in local_prefixes:
   long_distance[key1] = value1


(MRAB's comment about the foolishness of iterating through the dict
but testing for key == string_literal still applies, of course.)


Depending on what the OP's doing I might recommend just "normalizing"
the phone numbers before processing them, (i.e. stripping off the '1's
and possible breaking them up into tuples ('nnn', 'nnn', '').

~Simon
-- 
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Re: PExpect on Windows System Using Cygwin

[Dave Angel]

Kevin Holleran wrote:

Hello,

I downloaded and installed the pexpect module and wrote a script.  All is
well and good, but the script proved to be pretty useful and now I was asked
to run it as a scheduled task up on a server to run periodically.  I was
intending on simply packaging it up with Py2Exe and moving it to the server
that way.

However, when I went to test it, I received this error

Traceback (most recent call last):
  File "script.py", line 17, in 
import pexpect
  File "lib\site-packages\pexpect.py", line 85, in 
support it. Pexpect is intended for UNIX-like operating systems.""")
ImportError: No module named resource

A critical module was not found. Probably this operating system does not
support it. Pexpect is intended for UNIX-like operating systems.

So now I realize that when I was testing on my system, I run cygwin and so
everything worked fine

Is there a .dll that I can copy with it or anything so that it works without
having to install cygwin on the server that will be hosting this scheduled
task?

Thanks for any help.

Kevin

  
Why not just use the subprocess module?   It's built into the Windows 
distribution, and doesn't need cygwin.


DaveA
--
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Re: Doubley imported module caused devastating bug

[Daniel Stutzbach]

On Thu, Sep 24, 2009 at 2:51 PM, Ethan Furman  wrote:

> I believe that modules are imported only once
>

That's *mostly* true, but try this one:

A.py:
print 'Importing A'
import B

B.py:
print 'Importing B'
import A

Cashew:/tmp$ python2.5 B.py
Importing B
Importing A
Importing B

--
Daniel Stutzbach, Ph.D.
President, Stutzbach Enterprises, LLC 
-- 
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Re: IDE for python similar to visual basic

[J Sisson]

On Sun, Sep 13, 2009 at 6:25 AM, Nobody  wrote:

> On Fri, 11 Sep 2009 05:27:59 -0700, r wrote:
>


> > Sounds like "somebody" failed to get input
> > from their users at design time. Or "somebody" has the inability to
> > relate to their end users.
>
> You're assuming that there is some "right" answer which is appropriate for
> all users. There isn't.
>

I worked for a company that had a team composed of graphic artists, QA
types, etc...that did nothing but draw up GUI's, show them to customers,
revise them, write up runnable "dummies" of the approved GUI's, performed
usability studies with our customers using the dummy GUI's, and finally
handed the GUI's over to dev so they could put in the guts to make it "do
stuff".

"Bugs" or "Cases" involving the GUI needing revision because a button needed
to be moved for usability were *extremely* rare, and the GUI didn't require
an additional toolset that allowed end users to tweak them.

-- 
Computers are like air conditioners...
They quit working when you open Windows.
-- 
http://mail.python.org/mailman/listinfo/python-list

Re: Date using input

[Sean DiZazzo]

On Sep 24, 7:49 am, flebber  wrote:
> On Sep 24, 11:10 pm, flebber  wrote:
>
>
>
> > On Sep 24, 10:58 pm, Dave Angel  wrote:
>
> > > flebber.c...@gmail.com wrote:
> > > > I am using python 2.6.2, I haven't updated to 3.0 yet. No I have no
> > > > class or instructor, I am learning this myself. I have Hetlands book
> > > > "Beginning Python Novice to Professional and online documentation
> > > > books so Dive into Python, python.org etc.
>
> > > > Using the SPE editor.
>
> > > > I have currently only fully written basic psuedocode to give me a
> > > > basic framework to guide myself.
>
> > > > #Basic pseudocode
> > > > #Purpose to get raw input and calculate a score for a field of options
> > > > and return that
> > > > #score in a set in descending order.
> > > > #Multiple sets sould be written to the doc
>
> > > > #Obtain date
> > > > #Check if txt file with same date exists. If yes apphend to results to
> > > > file.
> > > > #Obtain location
> > > > #Set Dictionary
> > > > #Event number
> > > > #Obtain set size
> > > > #Prompt first entry
> > > > #First Entry Number
> > > > #First Entry Name
> > > > #Set Blocks to obtain and calculate data
> > > > #Block 1 example - Placings Block
> > > > #Obtain number of events competed in
> > > > #Obtain how many times finished first
> > > > #Ensure this value is not greater than Number of Events
> > > > #Number of Firsts divide by Events * total by 15.
> > > > #Obtain Second finishes
> > > > #Ensure this value is not greater than Number of Events
> > > > #Number of Seconds divide by Events * total by 10.
> > > > #Continue On with this
> > > > #Block 2 - Lookup coach Dict and apply value.
> > > > #Obtain Surname of Coach
> > > > #Lookup Coach File and Match Name and get value.
> > > > #Blocks continue gaining and calculating values.
> > > > #create txt file named using date
> > > > #Sum Values Block1 + Block2 etc
> > > > #Print to file event number and field with name number individual
> > > > Block totals and Sum Total
> > > > #Arranged in descending Sum Total.
> > > > #Prompt are there any more events? Yes return to start
> > > > #Apphend all additional events to same day file seperated by blank line.
>
> > > How many of these steps have you attempted actually coding?  Seems to me
> > > your first two steps are just string manipulation, and you only need to
> > > use the datetime module if you need to validate.  In other words, if the
> > > user specifies the date as 31/09/2009, you might want to later bounce
> > > back to him with a complaint that September only has 30 days.
>
> > > So the first task is to accept input in the form   ab/cd/efgh   and
> > > produce a string  efgh-cd-ab.log   which you will then create as a text
> > > file.  And if the file exists, you'll append to it instead of
> > > overwriting it.   Can you do that much?
>
> > > DaveA
>
> > Trying but haven't got it working, thats why I started to try and use
> > datetime module.
>
> Surely getting it tottally mixed up
>
> from datetime import date
> def ObtainDate(params):
>   date = raw_input("Type Date dd/mm/year: %2.0r%2.0r/%2.0r%2.0r/%4.0r
> %4.0r%4.0r%4.0r")
>  print date.datetime(year-month-day)
>  #Check if txt file with same date exists. If yes apphend to results
> to file.
> date.append(datetime
>
> and
>
> def ObtainDate(params):
>     date = raw_input("Type Date dd/mm/year: ")
>     date.format = (%4.0s%4.0s%4.0s%4.0s-%2.0s%2.0s-%2.0s)
>     print date.format

I think you are looking for datetime.strptime()

input = raw_input("Type Date dd/mm/year: ")
d = datetime.strptime(input, "%d/%m/%y")
print d

~Sean
-- 
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Anyone with Experience Using WinTV Capture Cards?

[W. eWatson]

A friend is looking for some help with how to use Python to access a 
WinTV (Go Plus) capture card, and how to display an image from it. Is 
there some facility that might help him, or does anyone have experience 
with such use that might suggest sources?

--
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Re: Evaluate coding and style

[Esmail]

Brown, Rodrick wrote:

I recently started playing with Python about 3 days now (Ex Perl guy) and 
wanted some input on style and structure of what I'm doing before I really 
start picking up some bad habits here is a simple test tool I wrote to validate 
home dirs on my system.

Please evaluate and let me know what could have been done better. Once again 
this is really my first time using python.


You may want to check out pylint (& pychecker)

Esmail

--
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Re: Re: Re: Date using input

[flebber . crue]

I don't think I am using re.compile properly, but thought as this would  
make my output an object it would be better for later, is that correct?


#Obtain date
def ObtainDate(date):
date = raw_input("Type Date dd/mm/year: ")
re.split('[/]+', date)
date
year = date[-1]
month = date[1]
day = date[0]
re.compile('year-month-day')


On Sep 25, 2009 8:32am, flebber.c...@gmail.com wrote:
Okay, thanks for the advice that sounds a good place to start. I  
used %2.os was an attempt to define width and precision to stop typo  
errors eg the user accidentally inputing 101/09/2009 or similar error. So  
that the __/__/ was adhered to.


I will go back to the start get the basics happening and then figure out  
a way to catch errors with format and correctness.



Thanks




On Sep 25, 2009 3:57am, Dave Angel da...@ieee.org> wrote:
> flebber wrote:
>
>
> On Sep 24, 11:10 pm, flebber flebber.c...@gmail.com> wrote:
>
>
>
>
> On Sep 24, 10:58 pm, Dave Angel da...@ieee.org> wrote:
>
>
>
>
>
>
>
>
>
>
> flebber.c...@gmail.com wrote:
>
>
>
>
> I am using python 2.6.2, I haven't updated to 3.0 yet. No I have no
>
> class or instructor, I am learning this myself. I have Hetlands book
>
> "Beginning Python Novice to Professional and online documentation
>
> books so Dive into Python, python.org etc.
>
> Using the SPE editor.
>
> I have currently only fully written basic psuedocode to give me a
>
> basic framework to guide myself.
>
> #Basic pseudocode
>
> #Purpose to get raw input and calculate a score for a field of options
>
> and return that
>
> #score in a set in descending order.
>
> #Multiple sets sould be written to the doc
>
> #Obtain date
>
> #Check if txt file with same date exists. If yes apphend to results to
>
> file.
>
> #Obtain location
>
> #Set Dictionary
>
> #Event number
>
> #Obtain set size
>
> #Prompt first entry
>
> #First Entry Number
>
> #First Entry Name
>
> #Set Blocks to obtain and calculate data
>
> #Block 1 example - Placings Block
>
> #Obtain number of events competed in
>
> #Obtain how many times finished first
>
> #Ensure this value is not greater than Number of Events
>
> #Number of Firsts divide by Events * total by 15.
>
> #Obtain Second finishes
>
> #Ensure this value is not greater than Number of Events
>
> #Number of Seconds divide by Events * total by 10.
>
> #Continue On with this
>
> #Block 2 - Lookup coach Dict and apply value.
>
> #Obtain Surname of Coach
>
> #Lookup Coach File and Match Name and get value.
>
> #Blocks continue gaining and calculating values.
>
> #create txt file named using date
>
> #Sum Values Block1 + Block2 etc
>
> #Print to file event number and field with name number individual
>
> Block totals and Sum Total
>
> #Arranged in descending Sum Total.
>
> #Prompt are there any more events? Yes return to start
>
> #Apphend all additional events to same day file seperated by blank line.
>
>
>
>
> How many of these steps have you attempted actually coding? Seems to me
>
> your first two steps are just string manipulation, and you only need to
>
> use the datetime module if you need to validate. In other words, if the
>
> user specifies the date as 31/09/2009, you might want to later bounce
>
> back to him with a complaint that September only has 30 days.
>
> So the first task is to accept input in the form ab/cd/efgh and
>
> produce a string efgh-cd-ab.log which you will then create as a text
>
> file. And if the file exists, you'll append to it instead of
>
> overwriting it. Can you do that much?
>
> DaveA
>
>
>
>
> Trying but haven't got it working, thats why I started to try and use
>
> datetime module.
>
>
>
>
>
>
> Surely getting it tottally mixed up
>
>
>
> from datetime import date
>
> def ObtainDate(params):
>
> date =aw_input("Type Date dd/mm/year: %2.0r%2.0r/%2.0r%2.0r/%4.0r
>
> %4.0r%4.0r%4.0r")
>
> print date.datetime(year-month-day)
>
> #Check if txt file with same date exists. If yes apphend to results
>
> to file.
>
> date.append(datetime
>
>
>
> and
>
>
>
> def ObtainDate(params):
>
> date =aw_input("Type Date dd/mm/year: ")
>
> date.format =%4.0s%4.0s%4.0s%4.0s-%2.0s%2.0s-%2.0s)
>
> print date.format
>
>
>
>
>
>
>
>
>
>
> As Tim says, first thing you want to do is rename that variable. You've  
defined two symbols with the same name.

>
>
>
> Then I'd ask what that %2.0r stuff is inside the prompt to the user.
>
>
>
> Do you understand what kind of data is returned by raw_input() ? If so,  
look at the available methods of that type, and see if there's one called  
split() that you can use to separate out the multiple parts of the user's  
response. You want to separate the dd from the mm and from the year.

>
>
>
> Once you've split the text, then you want to recombine it in a  
different order, and with dashes between the parts. If I were at your  
stage of experience, I'd not bother with the datetime module at all. Just  
see if you can rebuild the string you need, assuming the user has entered  
a valid 10-character string.

>
>
>
> Later you 

Poll: Do you use csv.Sniffer?

[skip]

If you are a csv module user, I have a question for you:  Do you use the
csv.Sniffer class?

o Yes, frequently
o Yes, on occasion
o I tried it a few times but don't use it now
o No, I don't need it
o No, never heard of it
o No (some other reason)

If you don't use it, how do you figure out the structure of your csv files?

o I just know
o I stumble around in the dark trying different parameters until the csv
  reader starts to spit out useful data

If csv.Sniff was to be removed from a future version of Python, how
difficult would it be to adapt?

o No problem
o No problem as long as you make it available via PyPI
o It would be a problem

If it would be a problem for you (which would not easily be solved by adding
it to PyPI), feel free to describe why it would be a challenge for you.  In
fact, please feel free to add any other comments you like to your response.

Private replies please.

Thanks,

-- 
Skip Montanaro - s...@pobox.com - http://www.smontanaro.net/
Getting old sucks, but it beats dying young
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Re: Screencapture of a video

[koranthala]

On Sep 24, 12:38 pm, koranthala  wrote:
> Hi,
>     I was trying to capture the video which I was viewing using
> Imagegrab module in PIL (windows). But, I found that the video was not
> captured at all. A quick googling tells me that it is because the
> windows does not have access to the viewing area.
>    Is there any way I can capture the video? It will be very helpful.

Any solutions? I found that basic printscreen can capture the video in
XP. In that case, it should be possible, I guess. Can anyone give me
some pointers?
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Re: PExpect on Windows System Using Cygwin

[Sean DiZazzo]

On Sep 24, 4:37 pm, Dave Angel  wrote:
> Kevin Holleran wrote:
> > Hello,
>
> > I downloaded and installed the pexpect module and wrote a script.  All is
> > well and good, but the script proved to be pretty useful and now I was asked
> > to run it as a scheduled task up on a server to run periodically.  I was
> > intending on simply packaging it up with Py2Exe and moving it to the server
> > that way.
>
> > However, when I went to test it, I received this error
>
> > Traceback (most recent call last):
> >   File "script.py", line 17, in 
> >     import pexpect
> >   File "lib\site-packages\pexpect.py", line 85, in 
> >     support it. Pexpect is intended for UNIX-like operating systems.""")
> > ImportError: No module named resource
>
> > A critical module was not found. Probably this operating system does not
> > support it. Pexpect is intended for UNIX-like operating systems.
>
> > So now I realize that when I was testing on my system, I run cygwin and so
> > everything worked fine
>
> > Is there a .dll that I can copy with it or anything so that it works without
> > having to install cygwin on the server that will be hosting this scheduled
> > task?
>
> > Thanks for any help.
>
> > Kevin
>
> Why not just use the subprocess module?   It's built into the Windows
> distribution, and doesn't need cygwin.
>
> DaveA

Can subprocess pass things like passwords to running processes like
pexpect can?

~Sean
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