Re: send() to a generator in a "for" loop with continue(val)??

[Michele Simionato]

On Apr 19, 8:09 am, Michele Simionato wrote:
> Coroutines instead could have been implemented as
> a library, without requiring any syntax change.

Here is a proof of principle, just to make clearer
what I have in mind. Suppose you have the following
library:

$ cat coroutine.py
from abc import abstractmethod

class Coroutine(object):
@abstractmethod
def main(self):
yield

def send(self, value):
if not hasattr(self, '_it'): # first call
self._it = self.main()
self._value = value
return self._it.next()

def recv(self):
return self._value

def close(self):
self._it.close()
del self._it
del self._value

Then you could write coroutines as follows:

$ cat coroutine_example.py
from coroutine import Coroutine

class C(Coroutine):
def main(self):
while True:
val = self.recv()
if not isinstance(val, int):
raise TypeError('Not an integer: %r' % val)
if val % 2 == 0:
yield 'even'
else:
yield 'odd'

if __name__ == '__main__':
c = C()
for val in (1, 2, 'x', 3):
try:
out = c.send(val)
except StopIteration:
break
except Exception, e:
print e
else:
print out

This is not really worse of what we do today with the yield
expression:

$ cat coroutine_today.py
def coroutine():
val = yield
while True:
if not isinstance(val, int):
raise TypeError('Not an integer: %r' % val)
if val % 2 == 0:
val = yield 'even'
else:
val = yield 'odd'

if __name__ == '__main__':
c = coroutine()
c.next()
for val in (1, 2, 'x', 3):
try:
out = c.send(val)
except StopIteration:
break
except Exception, e:
print e
else:
print out

Actually it is clearer, since it avoids common mistakes
such as forgetting the ``val = yield`` line in the coroutine
function and the ``c.next`` line right after instantiation
of the coroutine object, which are needed to initialize
the coroutine correctly.
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Re: Is there a programming language that is combination of Python andBasic?

[Hendrik van Rooyen]

 "Steven D'Aprano"  wrote:

COMEFROM on the other hand is just the purest evil imaginable.

*grin* - I expect you say this because it is a bit like COBOL's
alter - you cannot *see* it in place when you read the code, and 
the effect is only apparent at run time after the distant statement 
has been executed.

Kind of fun...

- Hendrik


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Re: Is there a programming language that is combination of Python andBasic?

[Hendrik van Rooyen]

 "Aaron Brady"  wrote:


On Apr 18, 4:44 am, "Hendrik van Rooyen"  wrote:

>> to untangle some spaghetti code. He did not mention if
>> the spaghetti was actually doing it's job, bug free, which
>> IMO is the only rational test for the quality of a piece
>
>I don't use 'rational' in the same way.  Do you mean objective?  Do
>readability, brevity, simplicity, purity, etc. contribute to quality?
>Is program quality equivalent (or identical) to code quality?

This paragraph illustrates the problem, I think:

Is there a significant difference between "rational" and "objective"?
Define "readability, brevity, simplicity, purity, etc" as applied
to the quality of a programme - it leads, inevitably, to a floundering
around in a wash of words.

However, to stop playing Devil's Advocate, there is such a thing
as code quality, but it cannot be defined, just like quality in general 
terms cannot be defined - as soon as you try, it turns to dross in
your hands.  Read Robert Pfirsig's "Zen and the art of motorcycle
maintenance" for a full explanation of this effect.

>> I do not agree with the reasoning that effectively says:
>> "If it is difficult to comprehend, it must be wrong"
>
>Wrong no, but impractical, possibly or probably or almost certainly,
>notwithstanding the subject-dependence of ease of comprehension.
>Simple code is more future-resilient than that which is difficult to
>comprehend, even holding the language (version) constant.  It is a

I think that the emphasis on future proofing code is actually overrated.

We try to code as if we are building pyramids, for all time, but the sad
experience is that only a tiny percentage of application code written has
a life of longer than about eight years.

8<--

>that of exploration, pioneering, research, and development.  However,
>even in simplest terms, some structures e.g. recursion, may be
>difficult to comprehend, but that doesn't mean they would be better
>more complicated.

This is true - the one does not imply the other, but the subtlety is that
it cuts either way - not more complicated, and not more simple.  One
has to strike a balance, and this is closer to an art than a science.
That said, however, throwing out the goto ( or even the more intriguing
comefrom ) is forcing the artist to paint while removing an element from
his palette - he has to work around the lack.

- Hendrik



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Re: Is there a programming language that is combination of Python andBasic?

[Hendrik van Rooyen]

 "BJörn Lindqvist"  wrote:

>I can somewhat sympathise with the op, neither python nor any other
>mainstream language can still do this:
>
>SCREEN 13
>PSET 160,100,255

Oh come on! Don't be like that!
Tell us what it does, please.

- Hendrik

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Re: Is there a programming language that is combination of PythonandBasic?

[Hendrik van Rooyen]

 Brian Blais   wrote:

>On Apr 18, 2009, at 5:44 , Hendrik van Rooyen wrote:

>>to untangle some spaghetti code.  He did not mention if
>>the spaghetti was actually doing it's job, bug free, which
>>IMO is the only rational test for the quality of a piece
>>of code, because it is the reason for its existence.  
>>The aesthetics are, like all aesthetics, a matter of opinion.
>
>
>Actually, I strongly disagree with this statement.  
>In my experience, there has been very very few 
>pieces of  code that I've written that I hadn't wanted 
>to *modify* at some point: extend it to a new set of 
>circumstances,  cover a different case, change the 
>output, etc...  The quality of a piece of code is not just 
>if it works right  now, but if you can reasonably extend 
>it for the future.  

Your experience is different from mine - in what I mostly
do, which is struggling around in embedded assembler,
by the time the thing "works" it is stable, and I very
seldom have to go back to fiddle with it. 

On the other hand, I understand what you are talking about,
but I think that the origen of the frustration that one feels
when having to battle with some old code, is actually inside
oneself - the code is the same, but I have changed, and I am 
no longer the same as I was when I wrote it.

>I toyed with Perl for a year or so, but couldn't give it 
>my full attention.  As a result, every few weeks when I 
>wanted to modify what I wrote, I had to re-learn the 
>code all over again because the syntax was so terse.
>The same is true for the typical use of a goto: you have 
>to relearn the program, because the flow jumps around.
>It's not just about aesthetics, but about being able to 
>work with a piece of code.

In my defense of the goto, I would like to make clear
that I do not support its use to produce spaghetti.
In general, muddled thinking, coupled with expediency,
is what I think are the true precursors of spaghetti code.
The goto is an innocent tool that can be used for good
or evil.

- Hendrik


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Re: Can some1 review my code?

[bearophileHUGS]

zaheer.ag...:
> I am asking free advice,The program is not very complex it is around
> 500 lines with most the code being reused,

500 lines is not a small Python program :-)
If you don't want to show it, then you can write another program, a
smaller one, for the purpose of letting people review it.

Bye,
bearophile
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Re: Is there a programming language that is combination of Python andBasic?

[Hendrik van Rooyen]

"Mensanator"  wrote:

8< -- description of bugs in spaghetti ---

Looks like that design really needed sorting out!

>A programmer once said to me "Why should I run it, I know
>how it works, I wrote it."

Are you serious? 
In my opinion, anybody who says this is not a programmer,
but merely an arrogant idiot with a lot of misplaced self-
confidence - somewhat like a permanent force corporal.

>
>My reply: "You only THINK you know how it works. _I_, on
>the other hand, ACTUALLY know how it works because I've
>run it."

How did you manage to keep your reply so meek?
You must be a really well brought up person.
:-)

- Hendrik


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Re: Can some1 review my code?

[liangguanhui]

On 4月19日, 下午2时18分, zaheer.ag...@gmail.com wrote:
> hi
>
> I am from java background, I have written some code that actually
> works :)
> Need to some one to look at it and tell me if there are better ways of
> doing same things
>
> Will some one help?
>
> Thanks

Post first, then someone will review, I think.
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Re: Useful MySQL Routines

[Tino Wildenhain]

Lawrence D'Oliveiro wrote:
I've done a writeup on some of the basic routines I frequently use here 
.


Why is that specific to mysql?

Btw, the bulkinserter could be better done by using executemany
and select usefull batch sizes. If you allow query construnction
better don't forget appropriate quoting of table- and column names
too to be on the safe side.

Regards
Tino
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Re: send() to a generator in a "for" loop with continue(val)??

[Peter Otten]

Aahz wrote:

> In article
> <07ad771b-a6d1-4f08-b16c-07caf7462...@e18g2000yqo.googlegroups.com>,
> Michele Simionato   wrote:
>>On Apr 18, 3:03=A0pm, a...@pythoncraft.com (Aahz) wrote:
>>> In article ,
>>> Peter Otten =A0<__pete...@web.de> wrote:

If it were up to me I'd rip out send() immediatly. At first I thought I
would see a compelling use case and be enlightened, but it never
happened.
>>>
>>> Too late -- it's likely to get an upgrade for 3.1 and 2.7. Basically,

Could you give some details or a link?

>>> send() is useful for coroutines, and if you haven't yet read
>>>http://dabeaz.com/coroutines/
>>> you really should (assuming you want to continue arguing).

I only just started reading Beazley's presentation, it looks interesting.
Thanks for the hint!

Are you currently using coroutines in Python? If so, what kind of practical
problems do they simplify for you?

>>I suspect Peter knows everything about coroutines and still he is not
>>convinced about .send. FWIW, I am sympathic with him.
> 
> Okay, I'm curious, is the argument that you shouldn't use generators for
> coroutines or something else?

I don't know nearly as much about coroutines as Michele thinks; in
particular I have no practical experience with them. 

What I've seen so far is that the once beautifully simple generator
mechanism has become very complex with the recent additions for ressource
management and coroutines.

Generators as filters and synthetic sequences are now ubiquitous, the with
statement is spreading like wildfire.

The send()/yield-expression duo on the other hand is limping along, and
someone like Michele who is definitely in the "intended audience" for the
more arcane features of Python says that you can do it with a library.
If that is possible shouldn't it have been the first step to put such a
library into the stdlib and see how it fares?

Generators at the moment seem to have turned into what in German we call
an "eierlegende Wollmilchsau"*.

Peter

(*)
http://www.pollux.franken.de/fileadmin/user_upload/images/eier-legende-wollmilchsau.jpg
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Re: Useful MySQL Routines

[Lawrence D'Oliveiro]

In message , Tino 
Wildenhain wrote:

> Lawrence D'Oliveiro wrote:
>> I've done a writeup on some of the basic routines I frequently use here
>> .
> 
> Why is that specific to mysql?

Because that's all I've used so far. Though sqlite looks interesting for 
single-user stuff...

> Btw, the bulkinserter could be better done by using executemany
> and select usefull batch sizes.

Hmm, I've never bothered with executemany. The code as written copes 
comfortably with 10,000 records or so.

> If you allow query construnction
> better don't forget appropriate quoting of table- and column names
> too to be on the safe side.

Hmm, I never worried about that, because I was I tried to be careful in the 
names I chose. And I've never allowed object names to come from user input 
:).

Besides, how do you deal with characters that are still illegal when quoted 
?

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can python access OS level features like bash scripting?

[Krishnakant]

Hello all,
Right now I am a bit confused on a final stage of my project.

I need to create an installer and an executable file for my python
program for gnu/linux.

The install script has to put the package into site-packages folder
where all other libraries reside.  Then put the executable file
into /usr/bin as other files.

The installer must also do the basic task of creating the database and
setting up password for on postgresql.
now here comes the main problem.
I believe putting files into proper places is pritty easy (may be some
one will instantly reply to the issue of putting the executable file and
libraries in place ).  But to do the database based activities, I need
python-psycopg2 module for postgresql in the first place.  So is it
possible for python to self download and install all the necessary
modules on to the client machine?

What further complicates the system is the fact that I want in future to
create 2 deb files, one for installing the gtk based client application
and the other to install the server side app made in python-twisted for
rpc.  Now the obvious problem is that first my python installation
(either 2.5 or 2.4) must check for itself if the modules are present or
not and if they are not present, my install utility must either download
it from net or if that's not the recommended approach then compile the
module from the source.

how do I achieve all this in python?
I know bash could be used to do such things but I don't want to use bash
because it is to clunky and won't run easily on windows.
Moreover I want to create a deb file as I said before so I want to keep
it as simple as possible.

Even regarding the executable, I am confused on using bash as the script
for writing the executable which can then do some thing like python -c
and call the modules, or write this executable code in a main.py and put
that file into the executable path i.e /usr/bin.

Please clear this mater so that I can go ahead.

I know the python list is pritty busy and I must thank all the members
who keep the spirit of the community and the professional organisations
alive so may be I will get a solution to my problem soon.

happy hacking.
Krishnakant.


  







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Re: Can some1 review my code?

[Martin P. Hellwig]

zaheer.ag...@gmail.com wrote:

hi

I am from java background, I have written some code that actually
works :)
Need to some one to look at it and tell me if there are better ways of
doing same things

Will some one help?

Thanks


My crystal ball is a bit cloudy today so forgive me if my suggestions 
may seem off-topic in your request.


I find that reviewing code that hasn't conform to 'standards' distracts 
me from the original intent. Parsing your code through a lint like 
PyLint will suggest 'standard' way of doing things (aim for 10/10) it 
will make things easier to read.


Also code that is unnecessary bloated (e.g. conditions that are never 
executed) can confuse the issue even more so. A good way would be to 
write unit-test against your code out of the perspective of the intended 
use (so not just to execute stuff because it is there) then run it 
through a coverage program. This will display nicely what code is 
executed and what not. The not part is what you look for in this 
perspective since if all the unit-test have what you need, why should 
the uncalled code be included?


Next stop comments, I am all for comments except if you need them to 
translate what the piece of code is doing there, if you can refactor 
your code so it looks more English and is understandable without 
comments (which should be still in there though) then do so.


For example:
range_8 = range(8)
for number in range_8:
# Loop through 0 to 7 and print it.
print(number)

instead of:
r = range(8)
for i in r:
# print i in range(8) loop
print(i)

* note this is a bad code example, only to clarify what I mean in general

Then look at your code from a functional perspective, if there are 
multiple functions that act in a similar way can you replace them with a 
single function? Then do so.


Is there functionality that looks so common that you think it should be 
in the standard library? It probably is then, make use of it.


Performance; run your code through a execution analyser like profile, do 
the numbers make sense? If not try to figure out why and replace the 
affected algorithm with one that makes more sense.


Finally memory;  Can you scrap duplicate entries of essential the same 
data, without affecting all the above? Might be a good idea to do so.


When done all this you might feel it is not necessary to review the code 
any more, which is then is a good moment to actually request a review :-)


I'll be happy to have a look at it though you might consider posting it 
here, more chance of useful feedback ;-)


--
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http://blog.dcuktec.com
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Re: Is there a programming language that is combination of PythonandBasic?

[Brian Blais]

On Apr 19, 2009, at 4:35 , Hendrik van Rooyen wrote:


 Brian Blais   wrote:


On Apr 18, 2009, at 5:44 , Hendrik van Rooyen wrote:



to untangle some spaghetti code.  He did not mention if
the spaghetti was actually doing it's job, bug free, which
IMO is the only rational test for the quality of a piece
of code, because it is the reason for its existence.
The aesthetics are, like all aesthetics, a matter of opinion.



Actually, I strongly disagree with this statement.
In my experience, there has been very very few
pieces of  code that I've written that I hadn't wanted
to *modify* at some point: extend it to a new set of
circumstances,  cover a different case, change the
output, etc...  The quality of a piece of code is not just
if it works right  now, but if you can reasonably extend
it for the future.


Your experience is different from mine - in what I mostly
do, which is struggling around in embedded assembler,
by the time the thing "works" it is stable, and I very
seldom have to go back to fiddle with it.

On the other hand, I understand what you are talking about,
but I think that the origen of the frustration that one feels
when having to battle with some old code, is actually inside
oneself - the code is the same, but I have changed, and I am
no longer the same as I was when I wrote it.


You're right about the person changing, not the code...for me it's  
mostly forgetting.  :)  I have found that python lets me re-learn my  
old code much faster (usually there is no re-learning necessary -  
just re-reading) then Perl, C, and Matlab.


As for fiddling with code, most of the code I write for work is for  
exploring ideas in theoretical neuroscience.  Once you have something  
that works, and you understand the problem, the next things out of  
your mouth is "I wonder what happens if this is changed?".  Change is  
the norm




In my defense of the goto, I would like to make clear
that I do not support its use to produce spaghetti.
In general, muddled thinking, coupled with expediency,
is what I think are the true precursors of spaghetti code.
The goto is an innocent tool that can be used for good
or evil.



as is true of any tool, but I think that the goto is a little too  
convenient for the sloppy thinker, and shouldn't be lying around to  
be picked up by just anyone.  :)



bb


--
Brian Blais
bbl...@bryant.edu
http://web.bryant.edu/~bblais



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Re: pyqt4 qTableWidget add items help

[Sebastian Wiesner]

-BEGIN PGP SIGNED MESSAGE-
Hash: SHA1


> from PyQt4 import  ?? QtGui? QtCore? Those are already loaded   other
> options are pyqtconfig and uic and those don't sound correct...

from PyQt4 import QtGui
QtGui.QTableWidgetItem

See [1] for an example.

[1] 
http://hg.lunaryorn.de/snippets/file/3272fdd93736/qt4_table_header_alignment.py

- -- 
Freedom is always the freedom of dissenters.
  (Rosa Luxemburg)
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Version: GnuPG v2.0.11 (GNU/Linux)

iEYEARECAAYFAknrGyYACgkQGV4vxEMMOxceGQCgky6GtUAOlyKxLLYCBWGYhwez
2zoAmgN9OecHib4imoxyn/FsLGaEIDw6
=EIsK
-END PGP SIGNATURE-

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Re: Is there a programming language that is combination of Python and Basic?

[Tim Wintle]

On Sun, 2009-04-19 at 06:26 +, Steven D'Aprano wrote:
> > (btw, how come nobody has mentioned python bytecode? Most flow
> control is jumps)
> 
> 
> I wrote yesterday:
> 
> "GOTO, after all, is just a jump, and we use jumps in Python all the
> time:
> 
> raise Exception
> break
> continue
> if... elif... else...
> for... else...
> etc."

Ah - apologies 

Tim

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Re: can python access OS level features like bash scripting?

[News123]

Hi,

I think you got lost in the wrong thread.
Though your subject line is correct your post threads under "Is there a
programming language, that . . . "

Perhaps you 'replied' to above thread and changed 'just' the subject line.

Chances to get an answer might be higher if you repost your question
without replying to an existing thread.



Krishnakant wrote:
> Hello all,
> Right now I am a bit confused on a final stage of my project.
> 
> I need to create an installer and an executable file for my python
> program for gnu/linux.
> 
> The install script has to put the package into site-packages folder
> where all other libraries reside.  Then put the executable file
> into /usr/bin as other files.
> 
> The installer must also do the basic task of creating the database and
> setting up password for on postgresql.
> now here comes the main problem.
> I believe putting files into proper places is pritty easy (may be some
> one will instantly reply to the issue of putting the executable file and
> libraries in place ).  But to do the database based activities, I need
> python-psycopg2 module for postgresql in the first place.  So is it
> possible for python to self download and install all the necessary
> modules on to the client machine?
> 
> What further complicates the system is the fact that I want in future to
> create 2 deb files, one for installing the gtk based client application
> and the other to install the server side app made in python-twisted for
> rpc.  Now the obvious problem is that first my python installation
> (either 2.5 or 2.4) must check for itself if the modules are present or
> not and if they are not present, my install utility must either download
> it from net or if that's not the recommended approach then compile the
> module from the source.
> 
> how do I achieve all this in python?
> I know bash could be used to do such things but I don't want to use bash
> because it is to clunky and won't run easily on windows.
> Moreover I want to create a deb file as I said before so I want to keep
> it as simple as possible.
> 
> Even regarding the executable, I am confused on using bash as the script
> for writing the executable which can then do some thing like python -c
> and call the modules, or write this executable code in a main.py and put
> that file into the executable path i.e /usr/bin.
> 
> Please clear this mater so that I can go ahead.
> 
> I know the python list is pritty busy and I must thank all the members
> who keep the spirit of the community and the professional organisations
> alive so may be I will get a solution to my problem soon.
> 
> happy hacking.
> Krishnakant.
> 
> 
>   
> 
> 
> 
> 
> 
> 
> 
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Re: Is there a programming language that is combination of Python and Basic?

[D'Arcy J.M. Cain]

On Sun, 19 Apr 2009 05:08:32 GMT
Zaphod  wrote:
> Friend of mine made a really nice asm development environment for his 
> home made OS.  Too bad he didn't have any marketing skills.

Was your friend's name Gary Kildall? :-)

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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: send() to a generator in a "for" loop with continue(val)??

[Aahz]

In article ,
Peter Otten  <__pete...@web.de> wrote:
>Aahz wrote:
>> In article
>> <07ad771b-a6d1-4f08-b16c-07caf7462...@e18g2000yqo.googlegroups.com>,
>> Michele Simionato   wrote:
>>>On Apr 18, 3:03=A0pm, a...@pythoncraft.com (Aahz) wrote:
 In article ,
 Peter Otten =A0<__pete...@web.de> wrote:
>
>If it were up to me I'd rip out send() immediatly. At first I thought I
>would see a compelling use case and be enlightened, but it never
>happened.

 Too late -- it's likely to get an upgrade for 3.1 and 2.7.
>
>Could you give some details or a link?

http://mail.python.org/pipermail/python-ideas/2009-April/004189.html

(You'll need to backtrack considerably to see the full discussion.)

>Are you currently using coroutines in Python? If so, what kind of practical
>problems do they simplify for you?

I'm not; I avoid coroutines like the plague.  ;-)  I much prefer nice,
simple threading...

>What I've seen so far is that the once beautifully simple generator
>mechanism has become very complex with the recent additions for ressource
>management and coroutines.
>
>The send()/yield-expression duo on the other hand is limping along, and
>someone like Michele who is definitely in the "intended audience" for the
>more arcane features of Python says that you can do it with a library.
>If that is possible shouldn't it have been the first step to put such a
>library into the stdlib and see how it fares?

You have a point; I wasn't paying much attention when send() was first
added, so I can't argue for it.  I'm just referring you to material I
happen to have handy that discusses use for it.
-- 
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"If you think it's expensive to hire a professional to do the job, wait
until you hire an amateur."  --Red Adair
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Re: send() to a generator in a "for" loop with continue(val)??

[Aahz]

In article ,
Peter Otten  <__pete...@web.de> wrote:
>
>Generators at the moment seem to have turned into what in German we call
>an "eierlegende Wollmilchsau"*.

One more point: there has always been a tension within the Python
community between people pushing the bleeding edge and people who prefer
to keep things simple.  Unfortunately, the former group tends to be much
more active.  :-(  There really needs to be a solid core of people who
are fundamentally conservative.  I like to think that I'm one of them
(and probably so do many other people in the python-dev community), but
each of us has our own hobby horses that we like to push, and none of us
keeps completely on top of everything.
-- 
Aahz (a...@pythoncraft.com)   <*> http://www.pythoncraft.com/

"If you think it's expensive to hire a professional to do the job, wait
until you hire an amateur."  --Red Adair
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Re: Is there a programming language that is combination of Python and Basic?

[Tim Hoffman]

I started my commercial programming in Business Basic, (actually MAI
Basic 4, and it's equivalent on primos (can't think of it's name at
the moment) then later BBX (Basis)

We ran the same code (all development on MAI, and then translated the
few differences programatically between MAI and Prime) and moved the
code via 1/4" tape to prime.

This was general ledger, policy and claims systems for an Insurance
Broker, we had about 300 + users on the two machines running over a
wide area serial network)

Then we moved to BBX on Unix.

Whilst we had goto, no such thing as string arrays (until BBX) etc
we really formally codified all of our devlopment standards, such that
even line number ranges where for specific tasks  (we had a limit of
64K per program, 1 -  for line numbers) and all initialisation had
to be in lines 1000 - 1099.   We where only allowed to use goto within
a routine and only as a last resort,. We could only have one return
from a gosub, etc. on mai we could only have two letter or letter
and digit variable names and they where global for the probram
so if you wanted loop local, or subroutine variables you could safely
use then x[1-9]  and y[1-9]
where safe, all initialisation setup use i[1-9] etc 

There where 3 programmers and we had to peer review everything.

We built rock solid systems, if I say so myself ;-)

You can write well structured and easily understood code in any
language, it just takes more discipline in some environments more than
others.

Having said that I would hate to go back to it from Python ;-)

See ya

T



On Apr 18, 4:52 am, a...@pythoncraft.com (Aahz) wrote:
> In article 
> ,
>
> baykus   wrote:
>
> >I am looking for one of those experimental languages that might be
> >combination of python+basic. Now thta sounds weird and awkward I know.
> >The reason I am asking is that I always liked how I could reference-
> >call certain line number back in the days. It would be interesting to
> >get similar functionality in Python.
>
> Why do you want to do that?  Before you answer, make sure to read this:
>
> http://www.u.arizona.edu/~rubinson/copyright_violations/Go_To_Conside...
> --
> Aahz (a...@pythoncraft.com)           <*>        http://www.pythoncraft.com/
>
> "If you think it's expensive to hire a professional to do the job, wait
> until you hire an amateur."  --Red Adair

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Re: can python access OS level features like bash scripting?

[Krishnakant]

sorry, but I was not replying to another thread.

My mistake.

happy hacking.
Krishnakant.



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Re: Can some1 review my code?

[zaheer . agadi]

> When done all this you might feel it is not necessary to review the code
> any more, which is then is a good moment to actually request a review :-)
>

> I'll be happy to have a look at it though you might consider posting it
> here, more chance of useful feedback ;-)

Great, Thanks a lot I will make sure that I complete what ever you
have listed here and then
request for a review. Well I understand that refusing to post the code
here in the mailing list might
annoy people and posting code here will only help it making it more
robust and clean. I am just being cautious that I don't break any of
the laws at my workplace.


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Re: wxPython 2.8 for Python 2.6 on Linux

[David Robinow]

On Sun, Apr 19, 2009 at 1:58 AM, Kenny x  wrote:
> Hello, I use Ubuntu 8.10 and the latest version of Python.
>
> I started programming wxPython on my Windows computer,
>
> but now I have access to my ubuntu box, and want wxPython for 2.6
>
> All the debs in the package manager are for 2.5, not 2.6
>
> How can I Install wxPython for Python 2.6 without building from the source?
>
> Any help appreciated, I need this solved! :)
>
> --
> http://mail.python.org/mailman/listinfo/python-list
>
>
I don't know. Why don't you ask Ubuntu?
How come you don't want to build from source?
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Re: Condition.wait(0.5) doesn't respect it's timeout

[Piet van Oostrum]

> stephane.bisin...@gmail.com (sb) wrote:

>sb> I'll also file a bug report because I am more and more convinced this
>sb> is a bug, if anything else at least in the documentation...

I looked at it more closely, and I found that the Condition.wait is
stuck on obtaining the GIL while the main thread executes the gobject
main loop. Therefore it also blocks on notifications, not only on the
timeout. 

It appears that GTK and Python threads are incompatible UNLESS you call
gtk.gdk.threads_init() before gtk.main(). In your case you can do it
after the import gtk in contact_list.py. Then it should work.

By the way, I wonder why you need a timeout in your wait. I think the
notifications should be sufficient to keep the gui updated.
-- 
Piet van Oostrum 
URL: http://pietvanoostrum.com [PGP 8DAE142BE17999C4]
Private email: p...@vanoostrum.org
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Re: Is there a programming language that is combination of Python andBasic?

[Aaron Brady]

On Apr 19, 3:05 am, "Hendrik van Rooyen"  wrote:
>  "Aaron Brady"  wrote:
>
> On Apr 18, 4:44 am, "Hendrik van Rooyen"  wrote:
>
> >> to untangle some spaghetti code. He did not mention if
> >> the spaghetti was actually doing it's job, bug free, which
> >> IMO is the only rational test for the quality of a piece
>
> >I don't use 'rational' in the same way.  Do you mean objective?  Do
> >readability, brevity, simplicity, purity, etc. contribute to quality?
> >Is program quality equivalent (or identical) to code quality?
>
> This paragraph illustrates the problem, I think:
>
> Is there a significant difference between "rational" and "objective"?
> Define "readability, brevity, simplicity, purity, etc" as applied
> to the quality of a programme - it leads, inevitably, to a floundering
> around in a wash of words.

It is an old philosopher's problem, that is, a problem of old
philosophers: do all rational wo/men behave the same given the same
situations, or more specifically, analogously given related
situations?

Rational and objective are related, I think.  An objective test of
code would be a process anyone can follow and derive the same result,
such as how many identifiers it contains.  A rational test involves
some sort of abstraction of humans, such as what the ultimately
rational human likes most, etc.  Objective partial credit on an exam,
for example, must come from a black-and-white rubric with exactly no
room for interpretation.  Rational partial credit could involve
inferences, guesses, and context, esp. acquaintance with the taker.

I agree that many of those traits are matters of degree and multi-
dimensional.  I am looking for an objective metric of code: code X has
traits P, Q, and R.  Period.  It would probably be simpler to start
describing code objectively, rather than trying to square-peg-round-
hole existing words.  However, there may be no objective test of
especially large sizes of code, and may fall to some sort of
interpretation or assessment of the most rational wo/man.

If I disagree with your measuring of a code with objective criteria,
we merely walk through the measurement, and resolve our disagreement
from the criteria upon discovering it.  If I disagree with your
measuring of it with rational criteria, we have to take into account
all sorts of trade-offs, such as long-short term, one-many readers,
different consequences, etc.  I'm speculating a little bit in defining
those words.

I advance that two equifunctional programs (same input-> same output)
can be compared w.r.t. brevity, to take an example, up to isomorphism
of identifier names, control structures, and statement order.  That
is, we can determine how brief code X is, disregarding identifier
names, and statement order where irrelevant.  Control structure
brevity might be something we're trying to measure:

while 1:
  if cond(): break

while not cond():
  ...

Are these equally brief, assuming they accomplish the same thing?  If
we don't have unanimous agreement on the answer to that question, we
must conclude that even brevity is a composite trait and we'll have to
start simpler.  A theory of traits would have to make concrete
predictions about *something*.  If some code has trait P, it will Q.

> However, to stop playing Devil's Advocate, there is such a thing
> as code quality, but it cannot be defined, just like quality in general
> terms cannot be defined - as soon as you try, it turns to dross in
> your hands.  Read Robert Pfirsig's "Zen and the art of motorcycle
> maintenance" for a full explanation of this effect.

Are you saying that quality reduces to how pleasant a particular
reader, or composite of multiple readers, finds the code?

"In the 1960s, programmers gave goto statements an average rating of 6
out of 10, 10 being most pleasing.  In the 70s, that rating dropped to
5 out of 10.  Subroutines were initially disliked, but came to be
favored, advancing from 4/10 in the 60s to 7/10 in the 80s and on.
Possible confounding variables include the increase in processor speed
and thus the increased forgivingness of running time of gosubs; the
prevalence of languages capable of generating subroutine calls; and
the efficiency of the particular calls generated, surveys of which
were not attempted."  --Fabrication

> >> I do not agree with the reasoning that effectively says:
> >> "If it is difficult to comprehend, it must be wrong"
>
> >Wrong no, but impractical, possibly or probably or almost certainly,
> >notwithstanding the subject-dependence of ease of comprehension.
> >Simple code is more future-resilient than that which is difficult to
> >comprehend, even holding the language (version) constant.  It is a
>
> I think that the emphasis on future proofing code is actually overrated.
>
> We try to code as if we are building pyramids, for all time, but the sad
> experience is that only a tiny percentage of application code written has
> a life of longer than about eight years.

Project managers should, I judge, be v

Re: Passing all extra commandline arguments to python program, Optparse raises exception

[David Stanek]

On Thu, Apr 16, 2009 at 10:05 AM, sapsi  wrote:
> Hello,
> Im using optparse and python 2.6 to parse some options, my commandline
> looks like
>
> prog [options] start|stop extra-args-i-will-pas-on
>
> The options are --b --c --d
>
> The extra options are varied are are passed onto another program e.g --
> quiet --no-command , my program doesnt care what these are but instead
> passes them onto another program.
>
> I know these will always follow start|stop.
>
> However optparse tries to process them and throws an exception - how
> can i prevent this without placing all the extra-args in quotes.
>


In Linux (maybe in Windows) you can tell an application to stop
processing args by using '--'. Given this code:
import sys
from optparse import OptionParser
op = OptionParser()
op.add_option('--a', dest='a', action='store_true', default=False)
op.add_option('--b', dest='b', action='store_true', default=False)
opts, args = op.parse_args(sys.argv)
print 'opts:', opts
print 'args:', args

Here is an example use:
eee0:~% python junk.py --a -- --c
{'a': True, 'b': False}
['junk.py', '--c']


-- 
David
blog: http://www.traceback.org
twitter: http://twitter.com/dstanek
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Re: can python access OS level features like bash scripting?

[Krishnakant]

hi very sorry for that 

On Sun, 2009-04-19 at 14:50 +0200, News123 wrote:
> Hi,
> 
> I think you got lost in the wrong thread.
> Though your subject line is correct your post threads under "Is there a
> programming language, that . . . "
> 
> Perhaps you 'replied' to above thread and changed 'just' the subject line.
> 
> Chances to get an answer might be higher if you repost your question
> without replying to an existing thread.
> I did not mean to do so, may be just missed out on removing the lines of the 
> previous thread.

sorry again.
I hope this becomes a new thread now and I get some productive reply.
happy hacking.
Krishnakant.




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Re: Condition.wait(0.5) doesn't respect it's timeout

[stephane . bisinger]

On Apr 18, 8:29 pm, Piet van Oostrum  wrote:
> 2. Importing in a thread is discouraged. I think it is cleaner to put
>    the import sys in the top of the module.

Yes I know I shouldn't import inside of threads, but that is something
that is going away, it's just for debugging this issue.

On Apr 19, 2:31 pm, Piet van Oostrum  wrote:
> I looked at it more closely, and I found that the Condition.wait is
> stuck on obtaining the GIL while the main thread executes the gobject
> main loop. Therefore it also blocks on notifications, not only on the
> timeout.

Ah-ha! My suspicions were right, then, I remembered something about
gobject being incompatible with python threads... but I couldn't find
anything in the docs, not even those of gobject, so I assumed my
memory was failing me...

> It appears that GTK and Python threads are incompatible UNLESS you call
> gtk.gdk.threads_init() before gtk.main(). In your case you can do it
> after the import gtk in contact_list.py. Then it should work.

I'll try to do that

> By the way, I wonder why you need a timeout in your wait. I think the
> notifications should be sufficient to keep the gui updated.

The reason is simple: when first downloading the contactss list,  I
receive a swarm of *Updated() calls, so if I redraw every time I get a
very bad visual effect and I waste a lot of CPU redrawing something
that will change in a very very short time. Hence the time
constraint... I couldn't come up with something smarter, so...

Anyway I wanted to really thank you for your time and your precious
advice, I really appreciate it!
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Re: Condition.wait(0.5) doesn't respect it's timeout

[stephane . bisinger]

On Apr 19, 2:31 pm, Piet van Oostrum  wrote:
> It appears that GTK and Python threads are incompatible UNLESS you call
> gtk.gdk.threads_init() before gtk.main(). In your case you can do it
> after the import gtk in contact_list.py. Then it should work.

Ok here's the deal: I'm not ending up in the gtk frontend. My code is
for the ncurses frontend, so there is no "import gtk" and "gtk.main()"
that gets executed in that case. But it is definitely around the
gobject thing, I'll try to search for this!
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wxPython 2.8 for Python 2.6

[Kenny x]

I hate building from the source.

Especially when wxPython has all these flags and I don't know what they
mean.

Is there any way?

I hate building from the source, and want to use Python 2.6 with wxPython
2.8
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Re: Condition.wait(0.5) doesn't respect it's timeout

[stephane . bisinger]

On Apr 19, 3:14 pm, stephane.bisin...@gmail.com wrote:
> Ok here's the deal: I'm not ending up in the gtk frontend. My code is
> for the ncurses frontend, so there is no "import gtk" and "gtk.main()"
> that gets executed in that case. But it is definitely around the
> gobject thing, I'll try to search for this!

gobject.threads_init() is what was missing, now everything works as
expected! Thanks!
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imaplib and smtplib

[Vistro]

I want to download a message from my Gmail inbox with imaplib, then forward
(basically resend it) with smtplib. I can log in with both. I just need to
know how to download a message with imaplib, and what needs to be converted
into what to be able to send it with smtplib.

For a good time, go to Start:Run and type in format C
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Re: Useful MySQL Routines

[Tino Wildenhain]

Lawrence D'Oliveiro wrote:
In message , Tino 
Wildenhain wrote:



Lawrence D'Oliveiro wrote:

I've done a writeup on some of the basic routines I frequently use here
.

Why is that specific to mysql?


Because that's all I've used so far. Though sqlite looks interesting for 
single-user stuff...


There are other more powerfull free alternatives to MySQL as well :)


Btw, the bulkinserter could be better done by using executemany
and select usefull batch sizes.


Hmm, I've never bothered with executemany. The code as written copes 
comfortably with 10,000 records or so.


Would be interesting to see the difference. However executemany
would be much more portable - and as I see it transfers at least
a bit less data over the wire.


If you allow query construnction
better don't forget appropriate quoting of table- and column names
too to be on the safe side.


Hmm, I never worried about that, because I was I tried to be careful in the 
names I chose. And I've never allowed object names to come from user input 
:).


Not you, but if others use it, it might be that they don't see a problem
and then - oops :)


Besides, how do you deal with characters that are still illegal when quoted 
?


Don't know. I personally avoid dealing with mysql altogether (I mean, 
commands hidden in sql comments? Heaven! :)


Cheers
Tino
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Re: can python access OS level features like bash scripting?

[Chris Jones]

On Sun, Apr 19, 2009 at 09:55:08AM EDT, Krishnakant wrote:
> hi very sorry for that 
> 
> On Sun, 2009-04-19 at 14:50 +0200, News123 wrote:
> > Hi,
> > 
> > I think you got lost in the wrong thread.
> > Though your subject line is correct your post threads under "Is there a
> > programming language, that . . . "
> > 
> > Perhaps you 'replied' to above thread and changed 'just' the subject line.
> > 
> > Chances to get an answer might be higher if you repost your question
> > without replying to an existing thread.
> > I did not mean to do so, may be just missed out on removing the lines of 
> > the previous thread.
> 
> sorry again.
> I hope this becomes a new thread now and I get some productive reply.
> happy hacking.
> Krishnakant.

No big deal, mature mailers such as mutt let you break threads into
subthreads via a painless "Alt-B".

CJ
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Re: Is there a programming language that is combination of Python andBasic?

[Scott David Daniels]

Hendrik van Rooyen wrote:

"Mensanator"  wrote:

8< -- description of bugs in spaghetti ---

Looks like that design really needed sorting out!


A programmer once said to me "Why should I run it, I know
how it works, I wrote it."


Are you serious? 
In my opinion, anybody who says this is not a programmer,

but merely an arrogant idiot with a lot of misplaced self-
confidence - somewhat like a permanent force corporal.


My reply: "You only THINK you know how it works. _I_, on
the other hand, ACTUALLY know how it works because I've
run it."


How did you manage to keep your reply so meek?
You must be a really well brought up person.
:-)


Possibly because the proper reply was probably, "You only THINK
you know how it works. _I_, on the other hand, know how it behaves,
even if I don't know how it was supposed to work."

--Scott David Daniels
scott.dani...@acm.org
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Re: Is there a programming language that is combination of PythonandBasic?

[Scott David Daniels]

Hendrik van Rooyen wrote:

In my defense of the goto, I would like to make clear
that I do not support its use to produce spaghetti.
In general, muddled thinking, coupled with expediency,
is what I think are the true precursors of spaghetti code.
The goto is an innocent tool that can be used for good
or evil.


The goto is a sharp, spiky dangerous tool that seduces
people into thinking of using it far too often.  It should
be used with the same respect you approach beautiful well-
armed people of questionable morals who you find attractive.

--Scott David Daniels
scott.dani...@acm.org
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Re: Condition.wait(0.5) doesn't respect it's timeout

[Aahz]

In article <6c04c7da-6b54-4a49-803f-aac3126e3...@f19g2000yqh.googlegroups.com>,
  wrote:
>On Apr 18, 8:29=A0pm, Piet van Oostrum  wrote:
>> 
>> By the way, I wonder why you need a timeout in your wait. I think the
>> notifications should be sufficient to keep the gui updated.
>
>The reason is simple: when first downloading the contactss list,  I
>receive a swarm of *Updated() calls, so if I redraw every time I get a
>very bad visual effect and I waste a lot of CPU redrawing something
>that will change in a very very short time. Hence the time
>constraint... I couldn't come up with something smarter, so...

The redraw thread should keep track of the last time it did a redraw;
each time it receives an update event, it should check to see whether it
has been more than a specified period of time since the last redraw.
-- 
Aahz (a...@pythoncraft.com)   <*> http://www.pythoncraft.com/

"If you think it's expensive to hire a professional to do the job, wait
until you hire an amateur."  --Red Adair
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Re: Is there a programming language that is combination of PythonandBasic?

[Chris Jones]

On Sun, Apr 19, 2009 at 04:35:27AM EDT, Hendrik van Rooyen wrote:
>  Brian Blais   wrote:
> 
> >On Apr 18, 2009, at 5:44 , Hendrik van Rooyen wrote:

> >>to untangle some spaghetti code.  He did not mention if the
> >>spaghetti was actually doing it's job, bug free, which IMO is the
> >>only rational test for the quality of a piece of code, because it is
> >>the reason for its existence.  The aesthetics are, like all
> >>aesthetics, a matter of opinion.

> >Actually, I strongly disagree with this statement.  In my experience,
> >there has been very very few pieces of  code that I've written that I
> >hadn't wanted to *modify* at some point: extend it to a new set of
> >circumstances,  cover a different case, change the output, etc...
> >The quality of a piece of code is not just if it works right  now,
> >but if you can reasonably extend it for the future.  

+1 .. obfuscated code never remains bug-free for long.

> Your experience is different from mine - in what I mostly do, which is
> struggling around in embedded assembler, by the time the thing "works"
> it is stable, and I very seldom have to go back to fiddle with it. 

Intellectually, assembler programming is the less demanding since its
level of abstraction does not go any further than mapping a few binary
numbers to a small set of usually well-chosen mnemonics. 

Unless it features a powerful macro-language that lets the apprentice
create his own high-level patois on top of the assembler, that is.

> On the other hand, I understand what you are talking about, but I
> think that the origen of the frustration that one feels when having to
> battle with some old code, is actually inside oneself - the code is
> the same, but I have changed, and I am no longer the same as I was
> when I wrote it.

> >I toyed with Perl for a year or so, but couldn't give it my full
> >attention.  As a result, every few weeks when I wanted to modify what
> >I wrote, I had to re-learn the code all over again because the syntax
> >was so terse.  The same is true for the typical use of a goto: you
> >have to relearn the program, because the flow jumps around.  It's not
> >just about aesthetics, but about being able to work with a piece of
> >code.

> In my defense of the goto, I would like to make clear that I do not
> support its use to produce spaghetti.  In general, muddled thinking,
> coupled with expediency, is what I think are the true precursors of
> spaghetti code.  The goto is an innocent tool that can be used for
> good or evil.

How true.

At least goto's have the merit of naming their target.

I have dealt with C code built on the original author's partiality for
200-line+ nested loops where it looked like every other line or so was
either a "break" or a "continue", goto's without the name that don't
clearly state where they are going.

Thank goodness he was not familiar with setjmp/longjmp.

:-)

CJ

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Python interpreter speed

[Ryniek90]

Hi.

Standard Python interpreter's implementation is written in C language. C 
code while compilation, is compilled into machine code (the fastest 
code). Python code is compiled into into byte-code which is also some 
sort of fast machine code. So why Python interpreter is slower than Java 
VM? Being written in C and compilled into machine code, it should be as 
fast as C/Asm code.

What's wrong with that?

Greets and thank you.
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Re: Is there a programming language that is combination of PythonandBasic?

[MRAB]

Chris Jones wrote:

On Sun, Apr 19, 2009 at 04:35:27AM EDT, Hendrik van Rooyen wrote:

 Brian Blais   wrote:


[snip]

In my defense of the goto, I would like to make clear that I do not
support its use to produce spaghetti.  In general, muddled thinking,
coupled with expediency, is what I think are the true precursors of
spaghetti code.  The goto is an innocent tool that can be used for
good or evil.


How true.

At least goto's have the merit of naming their target.


Except in (classic) Pascal where they are unsigned integers (they still
need to be declared).


I have dealt with C code built on the original author's partiality for
200-line+ nested loops where it looked like every other line or so was
either a "break" or a "continue", goto's without the name that don't
clearly state where they are going.

Thank goodness he was not familiar with setjmp/longjmp.


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Re: Python interpreter speed

[Krishnakant]

I don't mean to start a flame war, but a productive debate will be
wonderful.  I have been writing heavy applications in java for a few
years untill recent past.
My experience is that python is not just fast but also zippy and smooth
when it comes to running the applications.

Infact I have a couple of softwares which were re coded in python for
this very reason.  So I would like to know real facts on this arguement.

Let me mention that out of these 2 apps one is a distributed application
with an rpc layer and other is a normal back and front end database
driven software.  both have heavy load on them and do a lot of number
crunching and complex calculations.

happy hacking.
Krishnakant.

On Sun, 2009-04-19 at 18:11 +0200, Ryniek90 wrote:
> Hi.
> 
> Standard Python interpreter's implementation is written in C language. C 
> code while compilation, is compilled into machine code (the fastest 
> code). Python code is compiled into into byte-code which is also some 
> sort of fast machine code. So why Python interpreter is slower than Java 
> VM? Being written in C and compilled into machine code, it should be as 
> fast as C/Asm code.
> What's wrong with that?
> 
> Greets and thank you.
> --
> http://mail.python.org/mailman/listinfo/python-list

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Re: [ANN] pyxser-0.2r --- Python XML Serialization

[Daniel Molina Wegener]

-BEGIN PGP SIGNED MESSAGE-
Hash: SHA512

Stefan Behnel 
on Sunday 19 April 2009 02:25
wrote in comp.lang.python:


> Daniel Molina Wegener wrote:
>> * Every serilization is made into unicode objects.
> 
> Hmm, does that mean that when I serialise, I get a unicode object back?
> What about the XML declaration? How can a user create well-formed XML from
> your output? Or is that not the intention?

  Yes, if you serialize an object you get an XML string as
unicode object, since unicode objects supports UTF-8 and
some other encodings. Also you can deserialize the object ---
I mean convert the XML back to python object tree. Take a
look on the serializer output:

  http://coder.cl/software/pyxser/#id_example

> 
> Stefan


Best regards,
- -- 
 .O. | Daniel Molina Wegener   | FreeBSD & Linux
 ..O | dmw [at] coder [dot] cl | Open Standards
 OOO | http://coder.cl/| FOSS Developer

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Re: Condition.wait(0.5) doesn't respect it's timeout

[stephane . bisinger]

On Apr 19, 4:50 pm, a...@pythoncraft.com (Aahz) wrote:
> The redraw thread should keep track of the last time it did a redraw;
> each time it receives an update event, it should check to see whether it
> has been more than a specified period of time since the last redraw.

That's what I do ;)
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Re: Python interpreter speed

[Pascal Chambon]

Hello

I'm not expert in low level languages, but I'd say that Python and Java 
are "compiled" to bytecodes of similar level. The difference lies in the 
information contained in those bytecodes : java is statically typed, so 
attribute access and other basic operations are rather quick, allowing 
few levels of indirection. Whereas a python attribute lookup can involve 
a big number of operations (browsing the inheritance tree, querying 
__getattribute__, __get__ and all those magic methods...). That's in 
this "magic" of python that we have a loss of performance I think - 
that's both the power and the drawback of this (awesome) language.


Regards,
Pascal

PS : I guess core python developpers will have much more accurate things 
to say about it ^^


Ryniek90 a écrit :


Hi.

Standard Python interpreter's implementation is written in C language. 
C code while compilation, is compilled into machine code (the fastest 
code). Python code is compiled into into byte-code which is also some 
sort of fast machine code. So why Python interpreter is slower than 
Java VM? Being written in C and compilled into machine code, it should 
be as fast as C/Asm code.

What's wrong with that?

Greets and thank you.
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The Python standard library and PEP8

[Emmanuel Surleau]

Hi there,

Exploring the Python standard library, I was surprised to see that several 
packages (ConfigParser, logging...) use mixed case for methods all over the 
place. I assume that they were written back when the Python styling 
guidelines were not well-defined.

Given that it's rather irritating (not to mention violating the principle of 
least surprise) to have this inconsistency, wouldn't it make sense to clean 
up the API by marking old-style, mixed-case methods as deprecated (but 
keep them around anyway) and add equivalent methods following the 
lowercase_with_underscores convention?

On an unrelated note, it would be *really* nice to have a length property on 
strings. Even Java has that!

Cheers,

Emm
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Re: Is there a programming language that is combination of Python andBasic?

[Mensanator]

On Apr 19, 3:51�am, "Hendrik van Rooyen"  wrote:
> "Mensanator"  wrote:
>
> 8< -- description of bugs in spaghetti ---
>
> Looks like that design really needed sorting out!

Since I was translating to Pascal, I couldn't
emulate that code if I wanted to.

>
> >A programmer once said to me "Why should I run it, I know
> >how it works, I wrote it."
>
> Are you serious?

Absolutely.

> In my opinion, anybody who says this is not a programmer,
> but merely an arrogant idiot with a lot of misplaced self-
> confidence - somewhat like a permanent force corporal.

That might have contributed to the reason why we
din't sell too many systems.

The last product developed ran on an IBM RISC PC
using the PICK operating system. We sold nearly one.

>
>
>
> >My reply: "You only THINK you know how it works. _I_, on
> >the other hand, ACTUALLY know how it works because I've
> >run it."
>
> How did you manage to keep your reply so meek?

He got paid more than I did.

> You must be a really well brought up person.
> :-)

But not behind their backs. A program I created that
tested anuther programmer's attempt at making a hash
table was labeled HASHIT.

Said programmer was long gone when the customer called
and wanted to know why his 1 record database was
saying it was full when only 3000 employees had been
entered. Turned out that the hashing algorithm could
not access any more than 3000 of the 1 available
records. This isn't the kind of thing Field Service
is supposed to have to deal with.

>
> - Hendrik

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Re: Is there a programming language that is combination of Python andBasic?

[Mensanator]

On Apr 19, 10:12�am, Scott David Daniels 
wrote:
> Hendrik van Rooyen wrote:
> > "Mensanator"  wrote:
>
> > 8< -- description of bugs in spaghetti ---
>
> > Looks like that design really needed sorting out!
>
> >> A programmer once said to me "Why should I run it, I know
> >> how it works, I wrote it."
>
> > Are you serious?
> > In my opinion, anybody who says this is not a programmer,
> > but merely an arrogant idiot with a lot of misplaced self-
> > confidence - somewhat like a permanent force corporal.
>
> >> My reply: "You only THINK you know how it works. _I_, on
> >> the other hand, ACTUALLY know how it works because I've
> >> run it."
>
> > How did you manage to keep your reply so meek?
> > You must be a really well brought up person.
> > :-)
>
> Possibly because the proper reply was probably, "You only THINK
> you know how it works. _I_, on the other hand, know how it behaves,
> even if I don't know how it was supposed to work."

Probably more accurate as his .exe file crashed
immediately when executed. That's what lead me to
supect he never ran it.

>
> --Scott David Daniels
> scott.dani...@acm.org
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print as a function in 2.5 ?

[Stef Mientki]

hello,

For several reasons I still use Python version 2.5.
I understand that the print-statement will be replaced in Python version 
3.0.


At the moment I want to extend the print statement with an optional 
traceback.

So I've 2 options:
1- make a new function, like "eprint ()", where "e" stands for extended 
print

2- make a function "print()" that has the extended features

Now I guess that one of the reasons to change print from a statement to 
a function,

is the option to override and extend it.
If that's so, choice 2 would be the best choice.
Is that assumption correct ?

Suppose the second choice is the best,
I can now create a function "print",
and have the best of 2 worlds, get my extension and being prepared for 
the future.


def print ( *args ) :
   for arg in args :
   print arg,
   print (' Print Traceback ')
   do_extended printer actions

Now doesn't seem to be allowed,
nor is there an import from __future__  :-(

What's the best solution (other than moving to 2.6 or up ?

thanks,
Stef Mientki
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Interest in generational GC for Python

[Borked Pseudo Mailed]

Hello,

Is there any interest in generational garbage collection in Python these days ?

Anyone working on it ?

Thanks

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Re: Is there a programming language that is combination of Python and Basic?

[Zaphod]

On Sun, 19 Apr 2009 09:09:07 -0400, D'Arcy J.M. Cain wrote:

> On Sun, 19 Apr 2009 05:08:32 GMT
> Zaphod  wrote:
>> Friend of mine made a really nice asm development environment for his
>> home made OS.  Too bad he didn't have any marketing skills.
> 
> Was your friend's name Gary Kildall? :-)

Nope - Craig Carmichael.  The OS was originally called OMEN but later 
changed to Oases and was initially designed to run on 68k based 
machines.  Craig just loves 68k assembly - less hair pulling required 
than x86.
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Re: The Python standard library and PEP8

[Pascal Chambon]

I agree that there are still some styling inconsistencies in python 
stdlib, but I'm not advocating a cleaning because I've always found 
camelCase much prettier than those multi_underscore_methods :p


Concerning the length property of strings, isn't the __len__() method 
sufficient ?
I know they're not usual in OOP languages, but builtins like len() and 
iter() might be better anyway, since they deal with some magical 
problems (CF "special attributes lookups" in the python documentation)



Regards,
Pascal

Emmanuel Surleau a écrit :

Hi there,

Exploring the Python standard library, I was surprised to see that several 
packages (ConfigParser, logging...) use mixed case for methods all over the 
place. I assume that they were written back when the Python styling 
guidelines were not well-defined.


Given that it's rather irritating (not to mention violating the principle of 
least surprise) to have this inconsistency, wouldn't it make sense to clean 
up the API by marking old-style, mixed-case methods as deprecated (but 
keep them around anyway) and add equivalent methods following the 
lowercase_with_underscores convention?


On an unrelated note, it would be *really* nice to have a length property on 
strings. Even Java has that!


Cheers,

Emm
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Re: print as a function in 2.5 ?

[Christian Heimes]

Stef Mientki wrote:
> Now doesn't seem to be allowed,
> nor is there an import from __future__  :-(
> 
> What's the best solution (other than moving to 2.6 or up ?

The word 'print' is a reserved word like is, class or def. You can't
have a function named 'print' in Python 2.5. You have to call your
function eprint() or print_().

Christian

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Re: The Python standard library and PEP8

[Gabriel Genellina]

En Sun, 19 Apr 2009 13:43:10 -0300, Emmanuel Surleau  
 escribió:


Exploring the Python standard library, I was surprised to see that  
several
packages (ConfigParser, logging...) use mixed case for methods all over  
the

place. I assume that they were written back when the Python styling
guidelines were not well-defined.


The name policy changed in March 2004. Before that, PEP8 said:

Function Names

  Plain functions exported by a module can either use the CapWords
  style or lowercase (or lower_case_with_underscores).  There is
  no strong preference, but it seems that the CapWords style is
  used for functions that provide major functionality
  (e.g. nstools.WorldOpen()), while lowercase is used more for
  "utility" functions (e.g. pathhack.kos_root()).

The current version says:

Function Names

  Function names should be lowercase, with words separated by  
underscores

  as necessary to improve readability.

  mixedCase is allowed only in contexts where that's already the
  prevailing style (e.g. threading.py), to retain backwards  
compatibility.


Given that it's rather irritating (not to mention violating the  
principle of
least surprise) to have this inconsistency, wouldn't it make sense to  
clean

up the API by marking old-style, mixed-case methods as deprecated (but
keep them around anyway) and add equivalent methods following the
lowercase_with_underscores convention?


The threading module has such aliases, but there are no plans for mass  
renaming all the stdlib that I know of. You'll have to live with this  
inconsistency.


On an unrelated note, it would be *really* nice to have a length  
property on

strings. Even Java has that!


Why would it be nice to have? I never missed it...

--
Gabriel Genellina

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Re: print as a function in 2.5 ?

[Pascal Chambon]

Hello,

I had found some article on this some months ago, can't remember where 
exactly...


But if you don't want harassments, I'd just advise you to create a 
function with a properly specific name (like "exprint()"), and to make 
it mimic closely the signature and behaviour of Py3k's print() function.
That way, if one day you switch to upper versions, a simple mass text 
replacing operation on all your files will do it in an instant B-)


Regards,
Pascal

Stef Mientki a écrit :


hello,

For several reasons I still use Python version 2.5.
I understand that the print-statement will be replaced in Python 
version 3.0.


At the moment I want to extend the print statement with an optional 
traceback.

So I've 2 options:
1- make a new function, like "eprint ()", where "e" stands for 
extended print

2- make a function "print()" that has the extended features

Now I guess that one of the reasons to change print from a statement 
to a function,

is the option to override and extend it.
If that's so, choice 2 would be the best choice.
Is that assumption correct ?

Suppose the second choice is the best,
I can now create a function "print",
and have the best of 2 worlds, get my extension and being prepared for 
the future.


def print ( *args ) :
   for arg in args :
   print arg,
   print (' Print Traceback ')
   do_extended printer actions

Now doesn't seem to be allowed,
nor is there an import from __future__  :-(

What's the best solution (other than moving to 2.6 or up ?

thanks,
Stef Mientki
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Re: The Python standard library and PEP8

[Paul Hankin]

On Apr 19, 7:37 pm, "Gabriel Genellina" 
wrote:
> The threading module has such aliases, but there are no plans for mass  
> renaming all the stdlib that I know of. You'll have to live with this  
> inconsistency.

It's been fixed in Python 3.0!

--
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Re: can python access OS level features like bash scripting?

[Gabriel Genellina]

En Sun, 19 Apr 2009 08:16:15 -0300, Krishnakant   
escribió:



I need to create an installer and an executable file for my python
program for gnu/linux.

The install script has to put the package into site-packages folder
where all other libraries reside.  Then put the executable file
into /usr/bin as other files.


Write a setup.py script using the distutils package:
http://docs.python.org/distutils/index.html


I believe putting files into proper places is pritty easy (may be some
one will instantly reply to the issue of putting the executable file and
libraries in place ).  But to do the database based activities, I need
python-psycopg2 module for postgresql in the first place.  So is it
possible for python to self download and install all the necessary
modules on to the client machine?


You said you want to create a .deb -- list the required dependencies there.


Even regarding the executable, I am confused on using bash as the script
for writing the executable which can then do some thing like python -c
and call the modules, or write this executable code in a main.py and put
that file into the executable path i.e /usr/bin.


I've seen both a bash script with a single line: python path/to/main.py,  
and a Python script that just imports some modules and then calls the main  
function. Perhaps bash is more useful if your program (or any library)  
requires some environment variables to be set.


--
Gabriel Genellina

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Re: The Python standard library and PEP8

[Gabriel Genellina]

En Sun, 19 Apr 2009 14:52:23 -0300, Paul Hankin   
escribió:



On Apr 19, 7:37 pm, "Gabriel Genellina" 
wrote:

The threading module has such aliases, but there are no plans for mass  
renaming all the stdlib that I know of. You'll have to live with this  
inconsistency.


It's been fixed in Python 3.0!


What do you mean "fixed"?

Python 3.0.1 (r301:69561, Feb 13 2009, 20:04:18) [MSC v.1500 32 bit  
(Intel)] on win32

Type "help", "copyright", "credits" or "license" for more information.

from threading import Thread
t = Thread()
t.name = "foo"
t.getName()

'foo'

t.setName("bar")
t.name

'bar'

Both the old camelCase methods and the new property are still there.  
They're not even deprecated yet.


--
Gabriel Genellina

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Re: Is there a programming language that is combination of PythonandBasic?

[Scott David Daniels]

Chris Jones wrote:

...
Intellectually, assembler programming is the less demanding since its
level of abstraction does not go any further than mapping a few binary
numbers to a small set of usually well-chosen mnemonics. 


Unless it features a powerful macro-language that lets the apprentice
create his own high-level patois on top of the assembler, that is.


No, I've dealt with an assembler named 'SLOE' that had an elaborate
mechanism for laying out code in memory in a way that the CPU would
be happy with.  Between that and the instruction prefect, the thing
was famously called "immune to programming."

--Scott David Daniels
scott.dani...@acm.org
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Re: Condition.wait(0.5) doesn't respect it's timeout

[Piet van Oostrum]

> stephane.bisin...@gmail.com (sb) wrote:

>>> By the way, I wonder why you need a timeout in your wait. I think the
>>> notifications should be sufficient to keep the gui updated.

>sb> The reason is simple: when first downloading the contactss list,  I
>sb> receive a swarm of *Updated() calls, so if I redraw every time I get a
>sb> very bad visual effect and I waste a lot of CPU redrawing something
>sb> that will change in a very very short time. Hence the time
>sb> constraint... I couldn't come up with something smarter, so...

while time.time() - t < 0.5 or not self._modified:
print >> sys.stderr, "Going to sleep\n"
self._mod_lock.wait(timeout=1)
print >> sys.stderr, "Ok time to see if we must repaint"
self.__repaint()
t = time.time()

But the timeout thing will continue after that, so you have a continuous
polling loop which wastes some CPU time. I think what you want can be
more easily achieved by doing a sleep(0.5) before the outer while loop,
i.e. as the first statement in __thread_run.
-- 
Piet van Oostrum 
URL: http://pietvanoostrum.com [PGP 8DAE142BE17999C4]
Private email: p...@vanoostrum.org
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Re: Interest in generational GC for Python

[Scott David Daniels]

Borked Pseudo Mailed wrote:

Hello,

Is there any interest in generational garbage collection in Python these days ?

Anyone working on it ?

Thanks


Not really all that useful for CPython (you cannot move live objects,
without breaking faith with C-coded extensions).  PyPy would be where
to look for that work (and perhaps FePy or unladen swallow).

--Scott David Daniels
scott.dani...@acm.org
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Re: Overriding methods per-object

[Pavel Panchekha]

On Apr 18, 9:43 pm, Aaron Brady  wrote:
> On Apr 17, 9:41 pm, Steven D'Aprano 
> cybersource.com.au> wrote:
> > On Fri, 17 Apr 2009 18:22:49 -0700, Pavel Panchekha wrote:
> > > I've got an object which has a method, __nonzero__ The problem is, that
> > > method is attached to that object not that class
>
> > >> a = GeneralTypeOfObject()
> > >> a.__nonzero__ = lambda: False
> > >> a.__nonzero__()
> > > False
>
> > > But:
>
> > >> bool(a)
> > > True
>
> > > What to do?
>
> > (1) Don't do that.
>
> > (2) If you *really* have to do that, you can tell the class to look at
> > the instance:
>
> > class GeneralTypeOfObject(object):
> >     def __nonzero__(self):
> >         try:
> >             return self.__dict__['__nonzero__']
> >         except KeyError:
> >             return something
>
> snip
>
> I think you need to call the return, unlike you would in
> '__getattr__'.
>              return self.__dict__['__nonzero__']( )
>
> You're free to use a different name for the method too.
>              return self.custom_bool( )
>
> And you don't even have to implement an ABC.  Er... /have/ to, that
> is.

I got it working. Thanks!
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Re: The Python standard library and PEP8

[Emmanuel Surleau]

On Sunday 19 April 2009 19:37:59 Gabriel Genellina wrote:
> En Sun, 19 Apr 2009 13:43:10 -0300, Emmanuel Surleau
>
>  escribió:
> > Exploring the Python standard library, I was surprised to see that
> > several
> > packages (ConfigParser, logging...) use mixed case for methods all over
> > the
> > place. I assume that they were written back when the Python styling
> > guidelines were not well-defined.
>
> The name policy changed in March 2004. Before that, PEP8 said:
>
>  Function Names
>
>Plain functions exported by a module can either use the CapWords
>style or lowercase (or lower_case_with_underscores).  There is
>no strong preference, but it seems that the CapWords style is
>used for functions that provide major functionality
>(e.g. nstools.WorldOpen()), while lowercase is used more for
>"utility" functions (e.g. pathhack.kos_root()).
>
> The current version says:
>
>  Function Names
>
>Function names should be lowercase, with words separated by
> underscores
>as necessary to improve readability.
>
>mixedCase is allowed only in contexts where that's already the
>prevailing style (e.g. threading.py), to retain backwards
> compatibility.

Ah, that makes sense.

> > Given that it's rather irritating (not to mention violating the
> > principle of
> > least surprise) to have this inconsistency, wouldn't it make sense to
> > clean
> > up the API by marking old-style, mixed-case methods as deprecated (but
> > keep them around anyway) and add equivalent methods following the
> > lowercase_with_underscores convention?
>
> The threading module has such aliases, but there are no plans for mass
> renaming all the stdlib that I know of. You'll have to live with this
> inconsistency.

Damn.

> > On an unrelated note, it would be *really* nice to have a length
> > property on
> > strings. Even Java has that!

> Why would it be nice to have? I never missed it...

First off, it's pretty commonplace in OO languages. Secondly, given the 
number of methods available for the string objects, it is only natural to 
assume that dir("a") would show me a len() or length() or size() method. 
Having to use a function for such a mundane operation feels unnatural and 
not OO.

Cheers,

Emm
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Re: [ANN] pyxser-0.2r --- Python XML Serialization

[Stefan Behnel]

Daniel Molina Wegener wrote:
> Stefan Behnel 
> on Sunday 19 April 2009 02:25
> wrote in comp.lang.python:
> 
> 
>> Daniel Molina Wegener wrote:
>>> * Every serilization is made into unicode objects.
>> Hmm, does that mean that when I serialise, I get a unicode object back?
>> What about the XML declaration? How can a user create well-formed XML from
>> your output? Or is that not the intention?
> 
>   Yes, if you serialize an object you get an XML string as
> unicode object, since unicode objects supports UTF-8 and
> some other encodings.

That's not what I meant. I was wondering why you chose to use a unicode
string instead of a byte string (which XML is defined for). If your only
intention is to deserialise the unicode string into a tree, that may be
acceptable. However, as soon as you start writing the data to a file or
through a network pipe, or pass it to an XML parser, you'd better make it
well-formed XML. So you either need to encode it as UTF-8 (for which you do
not need a declaration), or you will need to encode it in a different byte
encoding, and then prepend a declaration yourself. In any case, this is a
lot more overhead (and cumbersome for users) than writing out a correctly
serialised byte string directly.

You seemed to be very interested in good performance, so I don't quite
understand why you want to require an additional step with a relatively
high performance impact that only makes it harder for users to use the tool
correctly.

Stefan
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Re: PEP 401

[Stefan Behnel]

alessiogiovanni.bar...@gmail.com wrote:
> Are 19 days that I read this PEP; it's all true?

Yep. Actually, the Cython project was lucky that the FLUFL did not
recognise it as an "alternative implementation of Python". That way, we can
easily finish up world domination, say, 10-20 years before Python on Parrot
reaches 2.7 feature completeness.

Stefan
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Re: How to create a virtual serial port?

[Nick Craig-Wood]

Grant Edwards  wrote:
>  On 2009-04-12, JanC  wrote:
> > Grant Edwards wrote:
> >
> >> On 2009-04-10, Stuart Davenport  wrote:
> >>
> >>> I am trying to work out if its possible, to create a virtual serial
> >>> port with Python?
> >>
> >> On Linux: no.
> >
> > I wonder if there is no way to emulate ptys from userspace?
> 
>  Didn't I just answer that question?
> 
>  On Linux: no.

Actually you could do it with an LD_PRELOAD library

Intercept open("/dev/ttyS0",...).  You'd need to intercept ioctl(),
read(), write(), close() etc too.

Messy but possible.

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How can I get path/name of the softlink to my python script when executing it

[Saravanan Shanmugham (sarvi)]

 
Hi,
I am writiing a script say "wabexec" in python
I will then have softlinks from other softlinks like  ls, waf,hello,
etc that are in the same directory and pointing to wabexec.
 
When some executes ./waf or ./hello and wabexec gets invoked because of
the softlink, how do I find out from within wabexec how it was invoked?
was it throug waf or hello, etc.
 
both __file__ and sys.arg0[] seem to have wabexec not the name of the
softlink.
 
Any ideas?
 
Sarvi
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Re: Condition.wait(0.5) doesn't respect it's timeout

[stephane . bisinger]

On Apr 19, 7:21 pm, Piet van Oostrum  wrote:
>                 while time.time() - t < 0.5 or not self._modified:
>                     print >> sys.stderr, "Going to sleep\n"
>                     self._mod_lock.wait(timeout=1)
>                     print >> sys.stderr, "Ok time to see if we must repaint"
>                 self.__repaint()
>                 t = time.time()
>
> But the timeout thing will continue after that, so you have a continuous
> polling loop which wastes some CPU time. I think what you want can be
> more easily achieved by doing a sleep(0.5) before the outer while loop,
> i.e. as the first statement in __thread_run.

Two boolean checks every half second is not a great waste; but
thinking about your solution I've come to agree that it is smarter and
more effective. Thank you again!
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Re: The Python standard library and PEP8

[Christian Heimes]

Emmanuel Surleau wrote:
> First off, it's pretty commonplace in OO languages. Secondly, given the 
> number of methods available for the string objects, it is only natural to 
> assume that dir("a") would show me a len() or length() or size() method. 
> Having to use a function for such a mundane operation feels unnatural and 
> not OO.

If you replace the term "OO" with "Java" in your posting, then I'm going
to agree with you. Neither Java nor Python are pure object oriented
languages. A while ago a friend of mine called Java a class centric
programming language. I think that describes Java's coding philosophy
very good. Python has a different coding philosphy. You can't assume
that Java style development works with Python (and vice versa).

Now to your rant about len(). Python class may implement several
protocols with magic methods like __len__(), __iter__() or
__getitem__(). The magic methods start and begin with two _. When a
method implements the __len__() method then it supports len(). In Python
readability counts. Try "import this" in a Python shell.

PEP 8 is a coding guideline for the standard library. It's not a law.
Some modules are older than the PEP, other modules and libraries were
developed outside the core and added later. We had a long discussion
about PEP8'ing more code but eventually we decided against it. More
chances would break too much 3rd party code.

Christian

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Re: The Python standard library and PEP8

[Gabriel Genellina]

En Sun, 19 Apr 2009 15:41:02 -0300, Emmanuel Surleau  
 escribió:

On Sunday 19 April 2009 19:37:59 Gabriel Genellina wrote:

En Sun, 19 Apr 2009 13:43:10 -0300, Emmanuel Surleau



> On an unrelated note, it would be *really* nice to have a length
> property on
> strings. Even Java has that!



Why would it be nice to have? I never missed it...


First off, it's pretty commonplace in OO languages. Secondly, given the
number of methods available for the string objects, it is only natural to
assume that dir("a") would show me a len() or length() or size() method.
Having to use a function for such a mundane operation feels unnatural and
not OO.


Perhaps in statically typed languages. Python is dynamic, so a x.length()  
requires a method lookup and that's expensive. len(x) on the contrary, can  
be optimized on a case by case basis -- it DOESN'T translate to  
x.__len__() as some might think.
See  
http://www.python.org/doc/faq/general/#why-does-python-use-methods-for-some-functionality-e-g-list-index-but-functions-for-other-e-g-len-list


On a side note, there is an alternative to dir(), more human-friendly:  
http://inky.github.com/see/


py> see("a")
  ?   []   in   +   *   %   <   <=   ==   !=   >   >=   len()
.capitalize()
  .center()   .count()   .decode()   .encode()   .endswith()
.expandtabs()

  .find()   .format()   .index()   .isalnum()   .isalpha()   .isdigit()
  .islower()   .isspace()   .istitle()   .isupper()   .join()   .ljust()
  .lower()   .lstrip()   .partition()   .replace()   .rfind()   .rindex()
  .rjust()   .rpartition()   .rsplit()   .rstrip()   .split()
.splitlines()
  .startswith()   .strip()   .swapcase()   .title()   .translate()
.upper()

  .zfill()

You can see len() there.

--
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Re: print as a function in 2.5 ?

[Tino Wildenhain]

Stef Mientki wrote:

hello,

For several reasons I still use Python version 2.5.
I understand that the print-statement will be replaced in Python version 
3.0.


At the moment I want to extend the print statement with an optional 
traceback.

So I've 2 options:
1- make a new function, like "eprint ()", where "e" stands for extended 
print

2- make a function "print()" that has the extended features


There is a 3rd option: hook yourself in the output stream and just
climb the call stack in the write() method. This works (done that
myself for easy debugging)

The other way if you want to selectively do so, either use
a form of log (because why must it be print if the output
is debugging information?) or instead of hooking sys.stdout,
use another output stream and print >>debug, ... to it.

Regards
Tino
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Re: print as a function in 2.5 ?

[Stef Mientki]

Tino Wildenhain wrote:

Stef Mientki wrote:

hello,

For several reasons I still use Python version 2.5.
I understand that the print-statement will be replaced in Python 
version 3.0.


At the moment I want to extend the print statement with an optional 
traceback.

So I've 2 options:
1- make a new function, like "eprint ()", where "e" stands for 
extended print

2- make a function "print()" that has the extended features


There is a 3rd option: hook yourself in the output stream and just
climb the call stack in the write() method. This works (done that
myself for easy debugging)

The other way if you want to selectively do so, either use
a form of log (because why must it be print if the output
is debugging information?) or instead of hooking sys.stdout,
use another output stream and print >>debug, ... to it.


thanks guys,
for the moment I'll stick to another name "v3print" so it can easily be 
replaced.

The third option (by Tino) looks interesting,
but is not suitable in my case,
because the program I'm writing is a kind of IDE (Integrated Development 
Environment),

where the user can create programs, and must have full control over stdout.

cheers,
Stef


Regards
Tino


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Re: The Python standard library and PEP8

[Carl Banks]

On Apr 19, 11:41 am, Emmanuel Surleau 
wrote:
> First off, it's pretty commonplace in OO languages. Secondly, given the
> number of methods available for the string objects, it is only natural to
> assume that dir("a") would show me a len() or length() or size() method.
> Having to use a function for such a mundane operation feels unnatural and
> not OO.


My advice in this situation is to think of len() as an operator that
has the syntax of a regular function.  Apart from not having special
syntax, len() is no different from any other operator.  It has an
associated method, __len__(), that allows objects to customize their
behavior when the operator is applied to them.

As to why they made len() and operator, it is really just a language
design decision.  By making len() into a function, rather than a
method, GvR was essentially saying, "Determining length of a sequence
is a common and familiar enough operation that it deserves status
above a mere method call, even if we don't have a special syntax for
it."

I am not, mind you, arguing either for or against len being an
operator (I don't really think it matters much either way); I'm just
saying there is a rationale behind it.


Carl Banks
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Re: The Python standard library and PEP8

[Aahz]

In article ,
Emmanuel Surleau   wrote:
>On Sunday 19 April 2009 19:37:59 Gabriel Genellina wrote:
>> En Sun, 19 Apr 2009 13:43:10 -0300, Emmanuel Surleau
>>  escribi=F3:
>>> 
>>> On an unrelated note, it would be *really* nice to have a length
>>> property on strings. Even Java has that!
>>
>> Why would it be nice to have? I never missed it...
>
>First off, it's pretty commonplace in OO languages.

What makes you think Python is "an OO language"?  What kind of OO
language allows you to do this:

def square(x):
return x*x

for i in range(10):
print square(x)
-- 
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"If you think it's expensive to hire a professional to do the job, wait
until you hire an amateur."  --Red Adair
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Re: The Python standard library and PEP8

[Emmanuel Surleau]

> Perhaps in statically typed languages. Python is dynamic, so a x.length()
> requires a method lookup and that's expensive. len(x) on the contrary, can
> be optimized on a case by case basis -- it DOESN'T translate to
> x.__len__() as some might think.
> See
> http://www.python.org/doc/faq/general/#why-does-python-use-methods-
for-some
>-functionality-e-g-list-index-but-functions-for-other-e-g-len-list

I don't know... the gist of the FAQ you link to is "that's legacy code and we 
don't want to change it in order not to break code". It doesn't try to justify 
the continued existence of len() and friends with technical arguments. I'll 
grant you that avoiding a method lookup is cheaper, another question is 
whether the difference would be noticeable in practice. I'd say that if 
methods were such a bad thing, that would put in question the 
implementation of the whole OO paradigm in Python, no?

> On a side note, there is an alternative to dir(), more human-friendly:
> http://inky.github.com/see/
>
> py> see("a")
>?   []   in   +   *   %   <   <=   ==   !=   >   >=   len()
> .capitalize()
>.center()   .count()   .decode()   .encode()   .endswith()
> .expandtabs()
>.find()   .format()   .index()   .isalnum()   .isalpha()   .isdigit()
>.islower()   .isspace()   .istitle()   .isupper()   .join()   .ljust()
>.lower()   .lstrip()   .partition()   .replace()   .rfind()   .rindex()
>.rjust()   .rpartition()   .rsplit()   .rstrip()   .split()
> .splitlines()
>.startswith()   .strip()   .swapcase()   .title()   .translate()
> .upper()
>.zfill()
>
> You can see len() there.

Nice! That's indeed more readable than dir().

Cheers,

Emm
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Re: The Python standard library and PEP8

[Emmanuel Surleau]

On Sunday 19 April 2009 21:46:46 Christian Heimes wrote:
> Emmanuel Surleau wrote:
> > First off, it's pretty commonplace in OO languages. Secondly, given the
> > number of methods available for the string objects, it is only natural to
> > assume that dir("a") would show me a len() or length() or size() method.
> > Having to use a function for such a mundane operation feels unnatural 
and
> > not OO.
>
> If you replace the term "OO" with "Java" in your posting, then I'm going
> to agree with you. Neither Java nor Python are pure object oriented
> languages. A while ago a friend of mine called Java a class centric
> programming language. I think that describes Java's coding philosophy
> very good. Python has a different coding philosphy. You can't assume
> that Java style development works with Python (and vice versa).

I don't know if it's "Java-style development" - you use a method to retrieve 
the length of a string in C++, Ruby or Javascript. Are you trying to say that 
having len() as a method/property is not object-oriented? The FAQ link in 
Gabriel Genellina's posting justifies the existence "len as a function" as 
historical. It does not seem to serve much purpose now. If there is a deeper 
reason why "len as a function" makes more sense than "len as a method", 
I'd be (genuinely) curious to hear it.

> Now to your rant about len(). Python class may implement several
> protocols with magic methods like __len__(), __iter__() or
> __getitem__(). The magic methods start and begin with two _. When a
> method implements the __len__() method then it supports len(). In Python
> readability counts. Try "import this" in a Python shell.

Not trying to attack you, but I'm not sure of what you're trying to say here. 
That len("a") is more readable than "a".len()?

> PEP 8 is a coding guideline for the standard library. It's not a law.
> Some modules are older than the PEP, other modules and libraries were
> developed outside the core and added later. We had a long discussion
> about PEP8'ing more code but eventually we decided against it. More
> chances would break too much 3rd party code.

I was not suggesting breaking. What's wrong with aliasing and marking as 
deprecated?

Also, given that Python 3000 breaks backward compatibility anyway, I don't 
see the point in not cleaning up the standard library completely and get rid 
of CamelCase once and for all.

Cheers,

Emm
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Re: The Python standard library and PEP8

[Emmanuel Surleau]

> What makes you think Python is "an OO language"? 

Python is a dynamic object-oriented programming language that can be used 
for many kinds of software development.

First line on the Python official website. Was this a trick question?

> What kind of OO
> language allows you to do this:
>
> def square(x):
> return x*x
>
> for i in range(10):
> print square(x)

Ruby, for instance.

Allowing for procedural-style programming does not mean that a language 
does not implement (even imperfectly) an OO paradigm.

Cheers,

Emm
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Re: How can I get path/name of the softlink to my python script when executing it

[Pascal Chambon]

Hello

I fear that in this case the whole indirection operations on softlink 
occur only in the shell, and that the final command is only executed as 
if it were called directly on the real file...


Have you tried typing "python ./waf", to see how the resolution occurs 
in that case ?


Regards,
Pascal



Saravanan Shanmugham (sarvi) a écrit :
 
Hi,

I am writiing a script say "wabexec" in python
I will then have softlinks from other softlinks like  ls, 
waf,hello, etc that are in the same directory and pointing to wabexec.
 
When some executes ./waf or ./hello and wabexec gets invoked because 
of the softlink, how do I find out from within wabexec how it was 
invoked? was it throug waf or hello, etc.
 
both __file__ and sys.arg0[] seem to have wabexec not the name of the 
softlink.
 
Any ideas?
 
Sarvi



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Re: can python access OS level features like bash scripting?

[Krishnakant]

On Sun, 2009-04-19 at 14:55 -0300, Gabriel Genellina wrote:

> Write a setup.py script using the distutils package:
> http://docs.python.org/distutils/index.html
> 
So that can distutil do the work of setting up the database and can it
find for itself if psycopg2 and other related libraries are installed?
I am going to create a deb file, so is it a good idea to some how have
the deb rules execute the setup.py file of the distutils?

Besides, I will also like to create a single file containing all the
modules i need as dependencies so even if a user does not have internet,
we can still install the package on that machine.

So will it be a good idea to let distutils do every thing I had
described about putting files in the place and having the script copyed
to /usr/bin etc?

happy hacking.
Krishnakant.
 


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Re: send() to a generator in a "for" loop with continue(val)??

[Dale Roberts]

On Apr 17, 10:07 pm, Aaron Brady  wrote:
> You can do it with a wrapping generator.  I'm not sure if it
> interferes with your needs.  It calls 'next' the first time, then just
> calls 'send' on the parameter with the value you send it.

Aaron,

Thanks for the hint. I'd made a modified version of my generator that
was "for loop aware" and had two yields in it, but this seemed very
fragile and hackish to me, and left my generator only usable inside a
"for" loop.

The wrapper method seems to be a much better way to go.

dale
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ANN: Mock 0.5.0 Release

[Fuzzyman]

Mock 0.5.0 has just been released.

* Mock Homepage http://www.voidspace.org.uk/python/mock/
* Download Mock 0.5.0 release (zip) 
http://www.voidspace.org.uk/downloads/mock-0.5.0.zip
* Mock Documentation as a PDF http://www.voidspace.org.uk/downloads/mock.pdf
* Mock entry on PyPI http://pypi.python.org/pypi/mock/
* Repository and Issue Tracker on Google Code http://code.google.com/p/mock/

This *isn't* backwards compatible as it cleans up the API in a few
ways, but they're all good changes I promise. {sm;:wink:}

One of the new features is that the Mock class now supports wrapping
objects; using the ``wraps`` keyword.

One of the other big changes is that the documentation is now built
with the ever-wonderful Sphinx, so the homepage is new and there also
a PDF of the documentation.

Mock is a library for the creation of simple mock objects that track
how they are used so that you can make assertions. It uses the action -
> assertion pattern rather than the record -> replay pattern. Action -
> assertion puts your tests after you have used the objects, which
seems more natural and means that you can make assertions about only
the behavior you are interested in. Mock also contains two decorators
(``patch`` and ``patch_object``) which make it easy to safely mock out
dependencies in the module under test purely within the scope of the
test itself (unpatching is done automatically on exit whether or not
the test passes). One of the changes in this release is that these
decorators also become context managers allowing them to be used with
the 'with statement'.

Mock can be installed with:

``easy_install mock``

The changelog for all changes in this release is:

* Made DEFAULT part of the public api.
* Documentation built with Sphinx.
* ``side_effect`` is now called with the same arguments as the mock is
called with and
  if returns a non-DEFAULT value that is automatically set as the
``mock.return_value``.
* ``wraps`` keyword argument used for wrapping objects (and passing
calls through to the wrapped object).
* ``Mock.reset`` renamed to ``Mock.reset_mock``, as reset is a common
API name.
* ``patch`` / ``patch_object`` are now context managers and can be
used with ``with``.
* A new 'create' keyword argument to patch and patch_object that
allows them to patch
  (and unpatch) attributes that don't exist. (Potentially unsafe to
use - it can allow
  you to have tests that pass when they are testing an API that
doesn't exist - use at
  your own risk!)
* The methods keyword argument to Mock has been removed and merged
with spec. The spec
  argument can now be a list of methods or an object to take the spec
from.
* Nested patches may now be applied in a different order (created
mocks passed
  in the opposite order). This is actually a bugfix.
* patch and patch_object now take a spec keyword argument. If spec is
  passed in as 'True' then the Mock created will take the object it is
replacing
  as its spec object. If the object being replaced is a class, then
the return
  value for the mock will also use the class as a spec.
* A Mock created without a spec will not attempt to mock any magic
methods / attributes
  (they will raise an ``AttributeError`` instead).

Many thanks to all those who gave feedback, feature requests and
patches!

What *isn't* in 0.5.0 is support for mocking magic methods. I do have
a technique in mind for this, which I implemented for the container
methods. It is very clean, but different from the pattern used to mock
out other methods. As I'm not currently using it I'm going to wait
until I need it and see if it works well in practise.

If you're interested in trying it, the code (with full documentation)
in a 'magics branch':

* http://code.google.com/p/mock/source/browse/#svn/branches/magics
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RE: How can I get path/name of the softlink to my python script when executing it

[Saravanan Shanmugham (sarvi)]

Sorry. I should have responded earlier to close this thread. It was my 
programming error.
 
Both sys.argv[0] and __file__ do point to the name and path of the softlink and 
not the actual program it is linked to.
 
So. Soryy. My bad programming got in my way.
 
Sarvi



From: Pascal Chambon [mailto:chambon.pas...@wanadoo.fr] 
Sent: Sunday, April 19, 2009 2:36 PM
To: Saravanan Shanmugham (sarvi)
Cc: python-list@python.org
Subject: Re: How can I get path/name of the softlink to my python script when 
executing it
Importance: High


Hello

I fear that in this case the whole indirection operations on softlink occur 
only in the shell, and that the final command is only executed as if it were 
called directly on the real file...

Have you tried typing "python ./waf", to see how the resolution occurs in that 
case ?

Regards, 
Pascal



Saravanan Shanmugham (sarvi) a écrit : 

 
Hi,
I am writiing a script say "wabexec" in python
I will then have softlinks from other softlinks like  ls, 
waf,hello, etc that are in the same directory and pointing to wabexec.
 
When some executes ./waf or ./hello and wabexec gets invoked because of 
the softlink, how do I find out from within wabexec how it was invoked? was it 
throug waf or hello, etc.
 
both __file__ and sys.arg0[] seem to have wabexec not the name of the 
softlink.
 
Any ideas?
 
Sarvi




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Re: send() to a generator in a "for" loop with continue(val)??

[Dale Roberts]

On Apr 19, 6:10 am, Peter Otten <__pete...@web.de> wrote:
> ...
> I only just started reading Beazley's presentation, it looks interesting.
> Thanks for the hint!
>
> Are you currently using coroutines in Python? If so, what kind of practical
> problems do they simplify for you?

I thought I'd chime in with an application too. I am using this
mechanism to implement a state machine. I read through Beazley's
presentation too - wow, lots of ideas in there.

For my simple state machine, I am using a very simple "trampoline"
function (see his slides starting at about #172). My "run" routine is
a bit different, but the idea is similar.

I'm using this to present images to a test subject (a person looking
at a computer screen), and the person's responses guide the state
machine. So I need to get data in (the subject responses) and out (the
next image to be presented).

So I have violated The Beazley Principle of slide #195:

Keeping it Straight
  • If you are going to use coroutines, it is critically
important to not mix programming paradigms
together
  • There are three main uses of yield
 • Iteration (a producer of data)
 • Receiving messages (a consumer)
 • A trap (cooperative multitasking)
  • Do NOT write generator functions that try to
do more than one of these at once

...whoops!

But I think this is a valid use of the mechanism, in that it is very
localized and self contained to just the few routines that make up the
state machine. It works very well, makes it easy to implement the
state machine clearly, and is easy to understand and maintain.

I can see where it could get very confusing to use this mechanism in a
more general way.

dale
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Re: The Python standard library and PEP8

[Martin P. Hellwig]

Emmanuel Surleau wrote:
What makes you think Python is "an OO language"? 


Python is a dynamic object-oriented programming language that can be used 
for many kinds of software development.


First line on the Python official website. Was this a trick question?


What kind of OO
language allows you to do this:

def square(x):
return x*x

for i in range(10):
print square(x)


Ruby, for instance.

Allowing for procedural-style programming does not mean that a language 
does not implement (even imperfectly) an OO paradigm.




Besides, calling Python Object-Orientated is a bit of an insult :-). I 
would say that Python is Ego-Orientated, it allows me to do what I want.


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Re: Is there a programming language that is combination of Python and Basic?

[Tim Rowe]

2009/4/19 Steven D'Aprano :

> "GOTO, after all, is just a jump, and we use jumps in Python all the time:
>
> raise Exception
> break
> continue
> if... elif... else...
> for... else...
> etc."

So as a syllogism:
P1: GOTO is a jump;
P2: GOTO is bad.
C: Jumps are  bad.

And then by showing the conclusion is false, you believe you have
shown a contradiction? Try looking up "Affirming the consequent"!

GOTO is an /unstructured/ jump. Raise, break, continue, if, for and so
an are all /structured/ jumps.

-- 
Tim Rowe
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Keyerror addhandler

[Steven Macintyre]

Hi all,

I'm wondering if anyone can assist me with this as I am very confused about
it now.

I am getting the following error;

Traceback (most recent call last):
  File "/usr/lib/python2.4/logging/config.py", line 191, in fileConfig
logger.addHandler(handlers[hand])
KeyError: 'handler_mylogfileHandler'

My code:

import logging
import logging.config
import logging.handlers

#parse config file
logging.config.fileConfig("logging.conf")

#create logger
logger = logging.getLogger("pythonacro")

my config:

[loggers]
keys=root,pythonacro

[handlers]
keys=consoleHandler,mylogfileHandler

[formatters]
keys=simpleFormatter

[logger_root]
level=DEBUG
handlers=consoleHandler

[logger_pythonacro]
level=DEBUG
handlers=consoleHandler,mylogfileHandler
propagate=1
qualname=pythonacro

[handler_consoleHandler]
class=StreamHandler
level=DEBUG
formatter=simpleFormatter
args=(sys.stdout,)

[handler_mylogfileHandler]
class=RotatingFileHandler
level=DEBUG
formatter=simpleFormatter
args=('python_acro.log', 'a', 125829120, 5)
filename=python_acro.log
mode=a

[formatter_simpleFormatter]
format=%(asctime)s - %(name)s - %(levelname)s - %(message)s
datefmt=

As far as I can tell, this is correct according to logging-config-fileformat
and documentation found on google.

Any ideas?

Many thanks

Steven



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Re: Keyerror addhandler

[Diez B. Roggisch]

Steven Macintyre schrieb:

Hi all,

I'm wondering if anyone can assist me with this as I am very confused about
it now.

I am getting the following error;

Traceback (most recent call last):
  File "/usr/lib/python2.4/logging/config.py", line 191, in fileConfig
logger.addHandler(handlers[hand])
KeyError: 'handler_mylogfileHandler'


For me, that fails with

mac-dir:tmp deets$ python2.5 test.py
Traceback (most recent call last):
  File "test.py", line 6, in 
logging.config.fileConfig("logging.conf")
  File 
"/Library/Frameworks/Python.framework/Versions/2.5/lib/python2.5/logging/config.py", 
line 84, in fileConfig

handlers = _install_handlers(cp, formatters)
  File 
"/Library/Frameworks/Python.framework/Versions/2.5/lib/python2.5/logging/config.py", 
line 149, in _install_handlers

klass = eval(klass, vars(logging))
  File "", line 1, in 
NameError: name 'RotatingFileHandler' is not defined
mac-dir:tmp deets$

Diez
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Re: Useful MySQL Routines

[Lawrence D'Oliveiro]

In message , Tino 
Wildenhain wrote:

> Lawrence D'Oliveiro wrote:
>
>> In message , Tino
>> Wildenhain wrote:
>> 
>>> Btw, the bulkinserter could be better done by using executemany
>>> and select usefull batch sizes.
>> 
>> Hmm, I've never bothered with executemany. The code as written copes
>> comfortably with 10,000 records or so.
> 
> Would be interesting to see the difference.

Go on, give it a try and let us know how it goes.

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Re: QT , Wxwidgets are not just UI framework ?

[Deep_Feelings]

thank you so much

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Re: The Python standard library and PEP8

[Dan Sommers]

On Sun, 19 Apr 2009 18:43:10 +0200, Emmanuel Surleau wrote:

> On an unrelated note, it would be *really* nice to have a length
> property on strings. Even Java has that!

And even in Java, they have sin(x) rather than x.sin().

Dan

-- 
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   wise north of the equator.
Atoms are not things. -- Werner Heisenberg  -- Dilbert's PHB

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Re: The Python standard library and PEP8

[Steven D'Aprano]

On Sun, 19 Apr 2009 13:46:23 -0700, Aahz wrote:

> What makes you think Python is "an OO language"?  

The fact that everything in Python is an object is a good hint.


> What kind of OO language allows you to do this:
> 
> def square(x):
> return x*x
> 
> for i in range(10):
> print square(x)

Python :)


The problem is, I believe, that people wrongly imagine that there is One 
True Way of a language being "object-oriented", and worse, that the OTW 
is the way Java does it. (If it were Smalltalk, they'd at least be able 
to make the argument that Smalltalk invented the perfect OO language and 
every change since then was corruption.) This is of course nonsense, but 
many people fall for it. "The way I'm used to is the One True Way".

As far as str.len versus len(str), apart from saving one character, I 
don't see any advantage to one over the other. It really depends on what 
you're used to.

It also depends on whether you see the length of a data structure as a 
property of the data, or the result of an operation ("counting") on the 
data structure. We often fall into the trap of saying such things as "the 
string HAS A length of 42" when what we really mean is "if you count the 
elements of the string we find 42 of them". I don't believe that the 
relationship between strings and length is a has-a relationship. I 
believe it is a property requiring a function (counting) to emerge, and 
therefore under OO principles, length should *not* be an attribute and 
Java et al are guilty of misuse of OO in making length an attribute.

If you don't agree, consider an analogy: think about what it means to say 
that "Fred has a height", compared to "Fred has a left arm". You can 
point to Fred's left arm, you can surgically remove it, in principle at 
least you could surgically attach a left arm to somebody who didn't have 
one. The relationship between "Fred" and "left arm" is most certainly a 
"has-a" relationship. But the same isn't true for height: you can't 
surgically remove Fred's height, and you can't even point to the part of 
Fred that is his height. The length of a string is like height.

(In practice, for speed, Python strings store their length in a field to 
avoid having to count it. But that's an optimization, it isn't 
fundamental to string length.)


-- 
Steven
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Re: Is there a programming language that is combination of Python and Basic?

[Steven D'Aprano]

On Sun, 19 Apr 2009 23:23:03 +0100, Tim Rowe wrote:

> 2009/4/19 Steven D'Aprano :
> 
>> "GOTO, after all, is just a jump, and we use jumps in Python all the
>> time:
>>
>> raise Exception
>> break
>> continue
>> if... elif... else...
>> for... else...
>> etc."
> 
> So as a syllogism:
> P1: GOTO is a jump;
> P2: GOTO is bad.
> C: Jumps are  bad.
> 
> And then by showing the conclusion is false, you believe you have shown
> a contradiction? Try looking up "Affirming the consequent"!

Sheesh. Talk about cherry-picking data. Go read my post in it's entirety, 
instead of quoting mining out of context. If you still think I'm unaware 
of the difference between unstructured GOTOs and structured jumps, or 
that I'm defending unstructured GOTOs, then you might have something 
useful to contribute.



-- 
Steven
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Re: The Python standard library and PEP8

[Aahz]

[BTW, please make sure to retain attributions for quotes]

In article ,
Emmanuel Surleau   wrote:
>Aahz:
>>
>> What makes you think Python is "an OO language"? 
>
>Python is a dynamic object-oriented programming language that can be used 
>for many kinds of software development.
>
>First line on the Python official website. Was this a trick question?

Yes.  Although Python is frequently described as "object-oriented", that
fails to capture all that is Pythonic; Python is also procedurally
oriented and has a lot of functional capabilities.  Don't mistake a
one-line blurb for an accurate description.

>> What kind of OO
>> language allows you to do this:
>>
>> def square(x):
>> return x*x
>>
>> for i in range(10):
>> print square(x)
>
>Ruby, for instance.
>
>Allowing for procedural-style programming does not mean that a language 
>does not implement (even imperfectly) an OO paradigm.

"Allowing" is the wrong term here.  Python absolutely encourages a
straightforward procedural style when appropriate; unlike Java, there is
no attempt to force object orientation everywhere.  Appealing to Python's
"object-oriented" nature when arguing about design decisions and ignoring
the other programming styles it supports is an indicator that you don't
really know Python very well.

Also, my code sample was itself a trick question.  Python has *dynamic*
object orientation (just as the blurb says), and square() will work
on any object with a __mul__() method (through the ``*`` syntax), just as
len() works on any object with a __len__() method.  So my code
demonstrates the way Python's programming styles interleave with each
other (throw in a listcomp to complete the set).

Here's a quote for you:

"Programming language design is not a rational science. Most reasoning
about it is at best rationalization of gut feelings, and at worst plain
wrong."  --GvR, python-ideas, 2009-3-1
-- 
Aahz (a...@pythoncraft.com)   <*> http://www.pythoncraft.com/

"If you think it's expensive to hire a professional to do the job, wait
until you hire an amateur."  --Red Adair
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Re: Interest in generational GC for Python

[Benjamin Peterson]

Borked Pseudo Mailed  pseudo.borked.net>
writes:

> 
> Hello,
> 
> Is there any interest in generational garbage
> collection
> in Python these days ?
> 
> Anyone working on it ?

The PyPy project has implemented more GC's than you want to
think about
including a ref counting gc, mark-sweep, and
several generational GCs and have
received excellent performance from them.
You should look at their new beta release.




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Re: Definition of Pythonic?

[Lawrence D'Oliveiro]

In message <49e30ac0$0$6828$5fc3...@news.tiscali.it>, Francesco Bochicchio 
wrote:

> Which is pretty sensible, since good engineering is often based more on
> choosing the right trade-off rather than choosing the One Right Thing to
> do.

Yes, but remember that, too, is a tradeoff. Moderation is fine, but don't 
carry it to extremes. You can never have too much moderation.

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Re: How to create an unclosed dialog in wxPython?

[Mike Driscoll]

On Apr 19, 4:36 am, liangguan...@gmail.com wrote:
> On 4月18日, 下午9时40分, 书虫  wrote:
>
> > In wxPython, after I create a wx.Frame, I want to create a modeless
> > and unclosed dialog. Here is my step:
>
> > app = wx.PySimpleApp()
> > f = wx.Frame(None, -1, "Test")
> > d = wx.Dialog(f, -1, "Test Dialog", style = wx.CAPTION)
> > f.Show()
> > d.Show()
> > app.MainLoop()
>
> > As you see, I create a dialog with wx.CAPTION style. And than, there
> > is no close button in this dialog. It seems unclosed dialog, but in
> > fact, if you enter Alt+F4 in this dialog, it will close. How could I
> > do?
>
> Binds the wx.EVT_CLOSE event and ignor it in the handle function.

This is the preferred method...there is a slight caveat that when you
actually want to close the dialog, you'll need to use the dialog's
Destroy() method...

- Mike
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Re: wxPython 2.8 for Python 2.6 on Linux

[Mike Driscoll]

On Apr 19, 8:30 am, David Robinow  wrote:
> On Sun, Apr 19, 2009 at 1:58 AM, Kenny x  wrote:
> > Hello, I use Ubuntu 8.10 and the latest version of Python.
>
> > I started programming wxPython on my Windows computer,
>
> > but now I have access to my ubuntu box, and want wxPython for 2.6
>
> > All the debs in the package manager are for 2.5, not 2.6
>
> > How can I Install wxPython for Python 2.6 without building from the source?
>
> > Any help appreciated, I need this solved! :)
>
> > --
> >http://mail.python.org/mailman/listinfo/python-list
>
> I don't know. Why don't you ask Ubuntu?
> How come you don't want to build from source?

Did you look at the wxPython wiki?

http://wiki.wxpython.org/InstallingOnUbuntuOrDebian

Try that. If it doesn't work, then you'll probably have to install
from source. However, I wouldn't bother with it and Python 2.6 until
wxPython's next release as there are some goofy things going on with
the manifest files. Maybe this doesn't affect Linux users
though...however, if you experience weird issues, that may be the
cause...or you didn't build it correctly.

If you need help building wxPython, please post to the wxPython list.

- Mike
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Re: [ANN] pyxser-0.2r --- Python XML Serialization

[Daniel Molina Wegener]

-BEGIN PGP SIGNED MESSAGE-
Hash: SHA512

Stefan Behnel 
on Sunday 19 April 2009 15:08
wrote in comp.lang.python:


> Daniel Molina Wegener wrote:
>> Stefan Behnel 
>> on Sunday 19 April 2009 02:25
>> wrote in comp.lang.python:
>> 
>> 
>>> Daniel Molina Wegener wrote:
 * Every serilization is made into unicode objects.
>>> Hmm, does that mean that when I serialise, I get a unicode object back?
>>> What about the XML declaration? How can a user create well-formed XML
>>> from your output? Or is that not the intention?
>> 
>>   Yes, if you serialize an object you get an XML string as
>> unicode object, since unicode objects supports UTF-8 and
>> some other encodings.
> 
> That's not what I meant. I was wondering why you chose to use a unicode
> string instead of a byte string (which XML is defined for). If your only
> intention is to deserialise the unicode string into a tree, that may be
> acceptable.

  Since libxml2 default encoding is UTF-8, and most applications are using
XML encoded in UTF-8, it's clear to define it as the default encoding for
the generated XML. Also, if take a little bit of time and read the
documentation, you can use any encoding supported by Python, such as
latin1, aka iso-8859-1. UTF-8 it's just the default encoding.

  The first intention was to have an C14N representation of python objects,
and regarding the C14N specification, I can't use another encoding for C14N
representation.

> However, as soon as you start writing the data to a file or 
> through a network pipe, or pass it to an XML parser, you'd better make it
> well-formed XML. So you either need to encode it as UTF-8 (for which you
> do not need a declaration),

  I repeat, it's just the default encoding. But do you which exception do
you get with byte strings and wrong encoded strings (think on accents and
special characters)?, Unicode objects in python support most of regular
encodings.

> or you will need to encode it in a different 
> byte encoding, and then prepend a declaration yourself. In any case, this
> is a lot more overhead (and cumbersome for users) than writing out a
> correctly serialised byte string directly.

  No, I'm just using the default encoding for libxml2 which can be converted
or reencoded to other character sets, and if read the documentation, you
will see that you can use most of python supported encodings.

> 
> You seemed to be very interested in good performance, so I don't quite
> understand why you want to require an additional step with a relatively
> high performance impact that only makes it harder for users to use the
> tool correctly.

  By using a different encoding than the default encoding for libxml2 makes
the work hard for libxml2 since it requires that every #PCDATA section to be
reencoded to the desired encoding and comparing one string conversion in
python against many string conversion under libxml2, the program gets more
slow performance by using a different encoding than the default encoding.
Also, since it is the default encoding, using an UTF-8 string in python
by passing the UTF-8 string buffer and size does not have a huge impact
on performance.

> 
> Stefan

Best regards,
- -- 
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 OOO | http://coder.cl/| FOSS Developer

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Re: QT , Wxwidgets are not just UI framework ?

[Old Listener]

On Apr 17, 10:20 am, Phil Thompson 
wrote:
> On Fri, 17 Apr 2009 07:04:40 -0700 (PDT), Deep_Feelings
>
>
>
>  wrote:
> > On Apr 17, 1:52 pm, "Diez B. Roggisch"  wrote:
> >> Deep_Feelings wrote:
> >> > qt include many libraries : network , threading,database ..etc while
> >> > Wxwidgets seem similar but with less scope
>
> >> > my question is : does these frameworks replace python's (or any other
> >> > language for that matter) built-in libraries ? or python does not
> >> > include that sort of libraries ?
>
> >> Some it includes, others it doesn't. And they come with different
> >> features.
>
> >> While python comes with a lot of included batteries, for some things you
> >> need a more powerful generator - that's where 3rd-party-libraries come
> >> into
> >> play.
>
> >> There are plenty of discussions about which GUI-toolkit is the best -
> >> google
> >> this group.
>
> >> However, mostly people agree that Qt is the most powerful, but often was
> >> debunked because of it's licensing. This has changed to the much more
> >> liberal LGPL for Qt4.5.
>
> >> Now it might be though that you'd still need to buy a license from Phil
> >> Thompson for his excellent PyQt-wrapping - but I'd personally say it's
> >> more
> >> worth than it actually costs given the power of Qt.
>
> >> Diez
>
> > thank you
>
> > considering that wxwidget is open source and free do you think that QT
> > lisencing is worth it ?
>
> wxWidgets, Qt and PyQt are all open source and free - just not the same
> open source license.
>
> Phil

Can PyQt be used in the Qt Creator IDE?
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Re: [ANN] pyxser-0.2r --- Python XML Serialization

[Daniel Molina Wegener]

-BEGIN PGP SIGNED MESSAGE-
Hash: SHA512

Stefan Behnel 
on Sunday 19 April 2009 15:08
wrote in comp.lang.python:


> Daniel Molina Wegener wrote:
>> Stefan Behnel 
>> on Sunday 19 April 2009 02:25
>> wrote in comp.lang.python:
>> 
>> 
>>> Daniel Molina Wegener wrote:
 * Every serilization is made into unicode objects.
>>> Hmm, does that mean that when I serialise, I get a unicode object back?
>>> What about the XML declaration? How can a user create well-formed XML
>>> from your output? Or is that not the intention?
>> 
>>   Yes, if you serialize an object you get an XML string as
>> unicode object, since unicode objects supports UTF-8 and
>> some other encodings.
> 
> That's not what I meant. I was wondering why you chose to use a unicode
> string instead of a byte string (which XML is defined for). If your only
> intention is to deserialise the unicode string into a tree, that may be
> acceptable. However, as soon as you start writing the data to a file or
> through a network pipe, or pass it to an XML parser, you'd better make it
> well-formed XML. So you either need to encode it as UTF-8 (for which you
> do not need a declaration), or you will need to encode it in a different
> byte encoding, and then prepend a declaration yourself. In any case, this
> is a lot more overhead (and cumbersome for users) than writing out a
> correctly serialised byte string directly.

  Sorry, it appears that I've misunderstand your question. By /unicode
objects/ I mean /python unicode objects/ aka /python unicode strings/.
Most of them can be reencoded into /latin*/ strings and then /ascii/
strings if is that what you want. But for most communications, suchs as
Java systems, utf-8 encoding goes as default. I've made pyxser to
generate interoperability between python and other systems.

> 
> You seemed to be very interested in good performance, so I don't quite
> understand why you want to require an additional step with a relatively
> high performance impact that only makes it harder for users to use the
> tool correctly.
> 
> Stefan

Atte.
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