Re: flattening a dict

[Duncan Booth]

Steven D'Aprano <[EMAIL PROTECTED]> wrote:

> # Untested
> def flattendict(d):
> def gen(L):
> return (x for M in exp(L) for x in rec(M))
> def exp(L):
> return (L+list(kv) for kv in L.pop().iteritems())
> def rec(M):
> return gen(M) if isinstance(M[-1],dict) else [M]
> return dict((tuple(L[:-1]),L[-1]) for L in gen([d]))
> 
> No. The function is hard to read, not because it uses lambdas, but 
> because it is obfuscated Python. The lambda syntax doesn't contribute
> to the obfuscation.

In this particular case I think the lambda does contribute to the
obfuscation. Yes, they are single expressions, but only because that
have been contorted to become single expressions. The first two return
generators, so if you don't force them into a lambda you can write them
out as for loops with yield. The last one is an if..else statement.
Splitting them into multiple statements also removes the need to keep
them as short as possible, so you don't need to use single letter
variable names everywhere. 


> And as for your point about bad code smells, no, I don't agree. If
> your function consists of a single expression, and you don't expect
> func.__name__ to have a meaningful value, then there's nothing wrong
> with using a "named lambda". Anonymous functions are first-class
> objects in Python, just as classes and modules and named functions
> are, and people shouldn't make up superstitious rules about not
> assigning them to names. 

You've got it backwards here: the lambdas were given names. If they hadn't 
been assigned to names I'd have no objection.
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Re: Error messages when using the Console Module

[peter]

> import sys
> sys.stdout = open("stdout.log","w")
> sys.stderr = open("stderr.log","w")
> print "This goes to stdout"
> print >>sys.stderr, "This goes to stderr"
>

This did the trick.  Thanks

Peter
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Re: usage of .encode('utf-8','xmlcharrefreplace')?

[7stud]

On Feb 19, 12:15 am, J Peyret <[EMAIL PROTECTED]> wrote:
> On Feb 18, 10:54 pm, 7stud <[EMAIL PROTECTED]> wrote:
>
> > One last point: you can't display a unicode string.  The very act of
> > trying to print a unicode string causes it to be converted to a
> > regular string.  If you try to display a unicode string without
> > explicitly encode()'ing it first, i.e. converting it to a regular
> > string using a specified secret code--a so called 'codec', python will
> > implicitly attempt to convert the unicode string to a regular string
> > using the default codec, which is usually set to ascii.
>
> Yes, the string above was obtained by printing, which got it into
> ASCII format, as you picked up.
> Something else to watch out for when posting unicode issues.
>
> The solution I ended up with was
>
> 1) Find out the encoding in the data file.
>
> In Ubuntu's gedit editor, menu 'Save As...' displays the encoding at
> the bottom of the save prompt dialog.
>
> ISO-8859-15 in my case.
>
> 2) Look up encoding corresponding to ISO-8859-15 at
>
> http://docs.python.org/lib/standard-encodings.html
>
> 3) Applying the decode/encode recipe suggested previously, for which I
> do understand the reason now.
>
> #converting rawdescr
> #from ISO-8859-15 (from the file)
> #to UTF-8 (what postgresql wants)
> #no error handler required.
> decodeddescr = rawdescr.decode('iso8859_15').encode('utf-8')
>
> postgresql insert is done using decodeddescr variable.
>
> Postgresql is happy, I'm happy.

Or, you can cheat.  If you are reading from a file, you can make set
it up so any string that you read from the file automatically gets
converted from its encoding to another encoding.  You don't even have
to be aware of the fact that a regular string has to be converted into
a unicode string before it can be converted to a regular string with a
different encoding. Check out the codecs module and the EncodedFile()
function:

import codecs

s = 'he Company\xef\xbf\xbds ticker'

f = open('data2.txt', 'w')
f.write(s)
f.close()

f = open('data2.txt')
f_special = codecs.EncodedFile(f, 'utf-8', 'iso8859_15')  #file, new
encoding, file's encoding
print f_special.read()  #If your display device understands utf-8, you
will see the troublesome character displayed.
#Are you sure that character is legitimate?

f.close()
f_special.close()




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Re: Garbage collection

[Simon Pickles]

Ken wrote:
> What is your __del__ method doing?
>   
Actually, nothing but printing a message when the object is deleted, 
just morbid curiosity.

I've yet to see one of the destructor messages, tho

>
>   from sys import getrefcount
>   print getrefcount(x)
>
>   
Perfect, thanks

Simon
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Re: average of PIL images

[vaneric]

> > def rgbTopixelvalue((r,g,b)):
> >alpha=255
> >return unpack("l", pack("", b, g, r, alpha))[0]
>
> That's much worse than averaging the R,G,B components.

oops!
the intention was to pack r,g,b components into a single value sothat
calculations like finding covariant matrix of a set of images etc can
be done..(i need to represent each image as an array of  values(either
long or float)..i can't work with an array of tuples of ints..

> As said above, try to compute using another color space, try HSL. The
> colorsys module can transform from/to RGB.

even if i convert from rgb to hsl i will have a tuple(h,s,l) for each
pixel and again i will have to convert it into a single value which i
can use in matrix multipln etc

is there a workaround sothat rgb color images can be worked on? any
advice most welcome..

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Re: Garbage collection

[Jarek Zgoda]

Duncan Booth napisał(a):

> Pretty much. If you have a __del__ method on an object then in the worst 
> case the only thing that can be guaranteed is that it will be called zero, 
> one or more than one times. (Admittedly the last of these only happens if 
> you work at it).
> 
> If it is called then is may be either immediately the last reference to the 
> object is lost, or it may be later when the garbage collector runs (and not 
> necessarily the first next time the garbage collector runs).

Java finalizers are not called upon VM exit, only when object is swept
by GC (for example when the object is destroyed upon program exit), the
CPython docs read that this is the case for Python too. Is this
behaviour standard for all VM implementations or is
implementation-dependent (CPython, Jython, IronPython)?

-- 
Jarek Zgoda
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"We read Knuth so you don't have to." (Tim Peters)
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Re: average of PIL images

[7stud]

On Feb 19, 12:13 am, "Gabriel Genellina" <[EMAIL PROTECTED]>
wrote:
> En Tue, 19 Feb 2008 04:01:04 -0200, vaneric <[EMAIL PROTECTED]>  
> escribió:
>
> > On Feb 19, 1:38 am, Robert Kern <[EMAIL PROTECTED]> wrote:
> >> Averaging color
> >> images is tricky; you really shouldn't do it in the RGB colorspace.
>
> > hi,
> > thanx for the guidance and detailed replies..I  tried  to pack the
> > r,g,b into a single value like below(something a member posted in the
> > past)
>
> > def rgbTopixelvalue((r,g,b)):
> >    alpha=255
> >    return unpack("l", pack("", b, g, r, alpha))[0]
>
> That's much worse than averaging the R,G,B components. First, you have to  
> omit the alfa value (or set it at the end). Then, consider this example:  
> (0,0,0)=black and (0,1,0)=almost black, average = (0,0,128)

How do you arrive at that average?
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Re: Garbage collection

[Duncan Booth]

Jarek Zgoda <[EMAIL PROTECTED]> wrote:

> Is that true assumption that __del__ has the same purpose (and same
> limitations, i.e. the are not guaranteed to be fired) as Java finalizer
> methods?

One other point I should have mentioned about __del__: if you are running 
under Windows and the user hits Ctrl+Break then unless you handle it Python 
will exit without doing any cleanup at all (as opposed to any other method 
of exiting such as Ctrl+C). If this matters to you then you can install a 
signal handler to catch the Ctrl+Break and exit cleanly.
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Re: Garbage collection

[Duncan Booth]

Jarek Zgoda <[EMAIL PROTECTED]> wrote:

> Ken napisa³(a):
> 
>> The good news is that you almost never have to do anything to clean up. 
>> My guess is that you might not even need to overload __del__ at all. 
>> People from a C++ background often mistakenly think that they have to
>> write destructors when in fact they do not.
> 
> Is that true assumption that __del__ has the same purpose (and same
> limitations, i.e. the are not guaranteed to be fired) as Java finalizer
> methods?
> 

Pretty much. If you have a __del__ method on an object then in the worst 
case the only thing that can be guaranteed is that it will be called zero, 
one or more than one times. (Admittedly the last of these only happens if 
you work at it).

If it is called then is may be either immediately the last reference to the 
object is lost, or it may be later when the garbage collector runs (and not 
necessarily the first next time the garbage collector runs).

The nasty case to watch for is when __del__ is called while the program is 
exiting: any global variables in the module may have already been cleared 
so you cannot be sure that you can reference anything other than attributes 
on the object being destroyed (and if you call methods on the same or other 
objects they may also find they cannot reference all their globals).

Fortunately cases when you actually need to use __del__ are very rare.
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Re: How to get current module object

[Gabriel Genellina]

On 19 feb, 03:33, Alex <[EMAIL PROTECTED]> wrote:
> GabrielGenellinawrote:
> > En Mon, 18 Feb 2008 14:49:02 -0200, Alex <[EMAIL PROTECTED]> escribió:
> >> That's what I've been searching for, thanks. By the way, I know it might
> >> be trivial question... but function and class namespaces have __name__
> >> attribute too. Why is global one always returned?
> > I don't understand the question (even with the later correction  
> > namespaces->objects)
>
> There's no question anymore, I just failed to distinguish function local
> variables (which don't include __name__) and function object's attributes>>> 
> Why do you want to get the module object? globals() returns the module
> >>> namespace, its __dict__, perhaps its only useful attribute...
>
> >> To pass it as a parameter to a function (in another module), so it can
> >> work with several modules ("plugins" for main program) in a similar  
> >> manner.
>
> > The function could receive a namespace to work with (a dictionary). Then  
> > you just call it with globals() == the namespace of the calling module.
>
> Yes, but access to module seems more verbose:
>
>  >>> module_dict['x']()
> xxx
>
> Instead of just:
>
>  >>> module.x()
> xxx

You could write a wrapper class on the client side, but I guess it's
easier to pass the module object directly, as you said earlier.
Anyway, this class would fake attribute access for dictionary entries:

py> class Idx2Attr(object):
...   def __init__(self, d): self.__dict__[None] = d
...   def __getattr__(self, name):
... try: return self.__dict__[None][name]
... except KeyError: raise NameError, name
...   def __setattr__(self, name, value):
... self.__dict__[None][name]=value
...
py> import htmllib
py> dir(htmllib)
['AS_IS', 'HTMLParseError', 'HTMLParser', '__all__', '__buil
tins__', '__doc__', '__file__', '__name__', 'sgmllib', 'test
']
py> mod = Idx2Attr(htmllib.__dict__) # htmllib.__dict__ is what you
get if you use globals() inside htmllib
py> mod.__file__
'C:\\APPS\\PYTHON25\\lib\\htmllib.pyc'
py> mod.foo = 3
py> htmllib.foo
3

([None] is to avoid name collisions to some extent)

--
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Re: Garbage collection

[Hrvoje Niksic]

Simon Pickles <[EMAIL PROTECTED]> writes:

> Ken wrote:
>> What is your __del__ method doing?
>>   
> Actually, nothing but printing a message when the object is deleted,
> just morbid curiosity.
>
> I've yet to see one of the destructor messages, tho

Do your objects participate in reference cycles?  In that case they
are deallocated by the cycle collector, and the cycle collector
doesn't invoke __del__.

>>> class X(object):
...   def __del__(self): print "gone"
...
>>> a = X()
>>> a = 1
gone
>>> b = X()
>>> b.someslot = b
>>> b = 1
>>> import gc
>>> gc.collect()
0
>>> 
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Re: average of PIL images

[Gabriel Genellina]

On 19 feb, 06:28, vaneric <[EMAIL PROTECTED]> wrote:
> > > def rgbTopixelvalue((r,g,b)):
> > >    alpha=255
> > >    return unpack("l", pack("", b, g, r, alpha))[0]
>
> > That's much worse than averaging the R,G,B components.
>
> oops!
> the intention was to pack r,g,b components into a single value sothat
> calculations like finding covariant matrix of a set of images etc can
> be done..(i need to represent each image as an array of  values(either
> long or float)..i can't work with an array of tuples of ints..
>
> > As said above, try to compute using another color space, try HSL. The
> > colorsys module can transform from/to RGB.
>
> even if i convert from rgb to hsl i will have a tuple(h,s,l) for each
> pixel and again i will have to convert it into a single value which i
> can use in matrix multipln etc
>
> is there a workaround sothat rgb color images can be worked on? any
> advice most welcome..

a) Work with the 3 components in parallel (that is, use 3 separate
matrices, one for each component, and regenerate the image at the
end).

b) Convert to grayscale (and lose the color information)

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Re: ANN: Phatch = PHoto bATCH processor and renamer based on PIL

[SPE - Stani's Python Editor]

On Feb 19, 4:23 am, "Daniel Fetchinson" <[EMAIL PROTECTED]>
wrote:
> On 2/18/08, SPE - Stani's Python Editor <[EMAIL PROTECTED]> wrote:
> > I'm pleased to announce the release of Phatch which is a
> > powerful batch processor and renamer. Phatch exposes a big part of the
> > Python Imaging Library through an user friendly GUI. (It is using
> > python-pyexiv2 to offer more extensive EXIF and IPTC support.) Phatch
> > is not targeted at manipulating individual pictures (such as with
> > Gimp), but repeating the same actions on hundreds or thousands of
> > images.
>
> > If you know PIL and have some nice recipes laying around, it is very
> > easy to write plugins as Phatch generates the corresponding GUI
> > automagically just like in Django. Any existings PIL scripts can be
> > added very easily. Let me know if you want to contribute or have any
> > questions.
>
> > Homepage:http://photobatch.stani.be(free download link below)
> > Tutorials:http://photobatch.wikidot.com/tutorials
> > Translations:https://translations.launchpad.net/phatch/trunk/+pots/phatch
> > License: GPLv3
> > Screenshot:
> >http://photobatch.wikidot.com/local--files/start/Screenshot-Phatch3d.jpg
> > (the perspective and reflection is produced by Phatch itself)

> This is pretty cool! I have one question about the equally cool
> website: what tool did you use for creating this image:
>
> http://photobatch.wikidot.com/local--files/start/Screenshot-Phatch3d.jpg
This is Phatchs own dogfood. I guess you missed the tutorials link.
There is a tutorial how you can achieve this effect:
http://photobatch.wikidot.com/tutorial-round-3d-reflect

I run Phatch on three screenshots I have to put them in perspective
with rounded corners and perspective. I let Phatch save them as a png
so transparency is preserved. Afterwards I opened Gimp and put the
three together on the background of a radial gradient.

Let me know if it works for you.

Stani
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Re: Double underscores -- ugly?

[Duncan Booth]

Berwyn <[EMAIL PROTECTED]> wrote:

>> Is it just me that thinks "__init__" is rather ugly? Not to mention
>> "if __name__ == '__main__': ..."?
> 
> That ugliness has long been my biggest bugbear with python, too.  The
> __name__ == '__main__' thing is something I always have to look up,
> every time I use it, too ... awkward.
> 
> I'd settle for:
> 
> hidden def init(self):  # which could be extended to work
> for everything "hidden x=3"
> ...
> 
> And for __name__ == '__main__' how about:
> 
> if sys.main():
> ...

Or even:

  @hidden
  def init(self): ...

@main
def mymainfunc():
   ...


The first of those probably wants some metaclass support to make it work 
cleanly, but here's a sample implementation for the second one:

import sys, atexit
def main(f):
"""Decorator for main function"""
def runner():
sys.exit(f())
if f.func_globals['__name__']=='__main__':
atexit.register(runner)
return f

print "define mymainfunc"
@main
def mymainfunc(args=sys.argv):
print "Got args", args
return 3
print "end of script"

If you have multiple functions marked as main that will run them in 
reverse order, so it might be better to put them on a list and use a 
single runner to clear the list. Also, I have no idea what happens to 
the exit code if you use this decorator more than once.

BTW, should anyone be wondering, you can still use atexit inside a 
function called from atexit and any registered functions are then called 
when the first one returns.
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Re: average of PIL images

[Gabriel Genellina]

On 19 feb, 06:55, 7stud <[EMAIL PROTECTED]> wrote:
> On Feb 19, 12:13 am, "Gabriel Genellina" <[EMAIL PROTECTED]>
> wrote:
> > En Tue, 19 Feb 2008 04:01:04 -0200, vaneric <[EMAIL PROTECTED]>  
> > escribió:
> > > On Feb 19, 1:38 am, Robert Kern <[EMAIL PROTECTED]> wrote:

> > >> Averaging color
> > >> images is tricky; you really shouldn't do it in the RGB colorspace.
>
> > > thanx for the guidance and detailed replies..I  tried  to pack the
> > > r,g,b into a single value like below(something a member posted in the
> > > past)
>
> > > def rgbTopixelvalue((r,g,b)):
> > >    alpha=255
> > >    return unpack("l", pack("", b, g, r, alpha))[0]
>
> > That's much worse than averaging the R,G,B components. First, you have to  
> > omit the alfa value (or set it at the end). Then, consider this example:  
> > (0,0,0)=black and (0,1,0)=almost black, average = (0,0,128)
>
> How do you arrive at that average?

(0,0,0) -> 0, (0,1,0) -> 256, (0+256)/2=128, 128 -> (0,0,128)
(ignoring alpha, or using alpha=0)

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Re: pyinstall and matplotlib

[Stef Mientki]

>>> Traceback (most recent call last):
>>>   File "multicolor.py", line 11, in ?
>>>   File "pylab.pyc", line 1, in ?
>>>   File "matplotlib\pylab.pyc", line 222, in ?
>>>   File "matplotlib\backends\__init__.pyc", line 24, in pylab_setup
>>>   File "matplotlib\backends\backend_tkagg.pyc", line 7, in ?
>>> ImportError: No module named Tkinter
>>> Any ideas?
>>> Thanks,
>> BTW: I don't use Tkinter for GUI, I use PythonCard and wxPython.  May
>> be the Tkinter is invoked by the multicolor.py sample?
> 
> I tried another application which I know for sure doesn't use Tkinter
> and yet it still tries to invoke Tkinter.  So, I need to disable the
> backend_tkagg.pyc somehow.
> 
> Any suggestions?
> 
> Thanks,

hi John,

I've started a discussion on the MatPlotLib list,
(and others, but now limited to matplotlib-list)
you might want to follow the discussion over there.
I just read that the real solution seems to be in setup.cfg,
and AFAIK that file is missing in the distro.

cheers,
Stef
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Re: The big shots

[Diez B. Roggisch]

[EMAIL PROTECTED] schrieb:
> I'm a little dissatisfied, and just thinking aloud.
> 
> Some of the ideas that have been proposed on Python-ideas as well as
> Python, have received partial evaluation from the alphas.
> 
> Lesser individuals than they could not have invented Python, and would
> be liable to ban me merely for this post.  Notwithstanding.
> 
> The reason they have cited is, "It is not in prevalent use."
> 
> The printing press, rail, automobiles, and Python, were not in
> prevalent use before their invention.  I.e., they -can't- come if one
> doesn't build it.  However, there were writing, transportation, and
> programming before these respectively; does it merely suffice to
> answer, "Yes it is?"
> 
> The Python gurus' combined professional judgement results in Python.
> 
> Looking through http://www.python.org/dev/peps/ , their own proposals
> don't meet their own criteria.  Start there.
> 
> It is neither necessary nor sufficient that an expansion is or would
> be used.

I don't get it as well - in all other open-source-communities I've been 
participating, the anonymous wacko shelling out half-baked, 
incomprehensible ideas faster than a gatling gun *immediately* had the 
full attention of the big-wigs, and after a short time became project lead.

No idea what's wrong with these people here - but I bet if you team up 
with Illias, you can start working on his language-to-rule-them-all in 
no time, shortening the delivery goal of 2011 immensly.

Looking-forward-to-it-ly yours,

Diez
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Re: Garbage collection

[Jarek Zgoda]

Ken napisał(a):

> The good news is that you almost never have to do anything to clean up. 
> My guess is that you might not even need to overload __del__ at all. 
> People from a C++ background often mistakenly think that they have to
> write destructors when in fact they do not.

Is that true assumption that __del__ has the same purpose (and same
limitations, i.e. the are not guaranteed to be fired) as Java finalizer
methods?

-- 
Jarek Zgoda
Skype: jzgoda | GTalk: [EMAIL PROTECTED] | voice: +48228430101

"We read Knuth so you don't have to." (Tim Peters)
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Re: flattening a dict

[Boris Borcic]

Duncan Booth wrote:

> In this particular case I think the lambda does contribute to the
> obfuscation. Yes, they are single expressions, but only because that
> have been contorted to become single expressions.  The first two return
> generators, so if you don't force them into a lambda you can write them
> out as for loops with yield. The last one is an if..else statement.

The key word is "become", and in this particular case the discussion thread is 
witness to the fact that it doesn't apply as you say. The three single 
expressions came about from a (misshappen, OK, but I never pretended otherwise) 
attempt to divide into pieces what was already a single expression in Arnaud's 
code while keeping in the spirit.

BTW, I have a particular issue with your statement :

 >> A lambda which is assigned directly to a variable is a bad code smell.

My problem is that I can't discuss its pure content with which I simply 
disagree, because that would legitimize its abstracted form with which I have 
the strongest issues, although largely OT.

Best, BB

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Rsync

[Felipe Coutinho]

Is there any thing in python that synchronize directories like rsync?

-- 
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CFP: DTVCS 2008 - Design, Testing and Formal Verification Techniques for Integrated Circuits and Systems

[ss DTVCS]

Apologies for any multiple copies received. We would appreciate it if you
could distribute
the following call for papers to any relevant mailing lists you know of.

 CALL FOR PAPERS

Special Session: Design, Testing and Formal Verification Techniques for
Integrated Circuits and Systems

DTVCS 2008

 August 18-20, 2008 (Kailua-Kona, Hawaii, USA)
 http://digilander.libero.it/systemcfl/dtvcs
=


Special Session in the IASTED International Conference on Circuits and
Systems (CS 2008)
-
The IASTED International Conference on Circuits and Systems (CS 2008) will
take place in
Kailua-Kona, Hawaii, USA, August 18-20, 2008.
URL: http://www.iasted.org/conferences/cfp-625.html.


Aims and Scope
---
The main target of the Special Session DTVCS is to bring together
engineering researchers,
computer scientists, practitioners and people from industry to exchange
theories, ideas,
techniques and experiences related to the areas of design, testing and
formal verification techniques
for integrated circuits and systems. Contributions on UML and formal
paradigms based on process algebras,
petri-nets, automaton theory and BDDs in the context of design, testing and
formal verification techniques
for integrated circuits and systems are also encouraged.

Topics
--
Topics of interest include, but are not limited to, the following:

* digital, analog, mixed-signal and RF test
* built-in self test
* ATPG
* theory and foundations: model checking, SAT-based methods, use of PSL,
compositional methods and probabilistic methods
* applications of formal methods: equivalence checking, CSP applications and
transaction-level verification
* verification through hybrid techniques
* verification methods based on hardware description/system-level languages
(e.g. VHDL, SystemVerilog and SystemC)
* testing and verification applications: tools, industrial experience
reports and case studies

Industrial Collaborators and Sponsors

This special session is partnered with:

* CEOL: Centre for Efficiency-Oriented Languages "Towards improved software
timing",
  University College Cork, Ireland (http://www.ceol.ucc.ie)
* International Software and Productivity Engineering Institute, USA (
http://www.intspei.com)
* Intelligent Support Ltd., United Kingdom (http://www.isupport-ltd.co.uk)
* Minteos, Italy (http://www.minteos.com)
* M.O.S.T., Italy (http://www.most.it)
* Electronic Center, Italy (http://www.el-center.com)
* Legale Fiscale, Italy (http://www.legalefiscale.it)

This special session is sponsored by:

* LS Industrial Systems, South Korea (http://eng.lsis.biz)
* Solari, Hong Kong (http://www.solari-hk.com/)

Technical Program Committee

* Prof. Vladimir Hahanov, Kharkov National University of Radio Electronics,
Ukraine
* Prof. Paolo Prinetto, Politecnico di Torino, Italy
* Prof. Alberto Macii, Politecnico di Torino, Italy
* Prof. Joongho Choi, University of Seoul, South Korea
* Prof. Wei Li, Fudan University, China
* Prof. Michel Schellekens, University College Cork, Ireland
* Prof. Franco Fummi, University of Verona, Italy
* Prof. Jun-Dong Cho, Sung Kyun Kwan University, South Korea
* Prof. AHM Zahirul Alam, International Islamic University Malaysia,
Malaysia
* Prof. Gregory Provan, University College Cork, Ireland
* Dr. Emanuel Popovici, University College Cork, Ireland
* Dr. Jong-Kug Seon, System LSI Lab., LS Industrial Systems Co. Ltd., South
Korea
* Dr. Umberto Rossi, STMicroelectronics, Italy
* Dr. Graziano Pravadelli, University of Verona, Italy
* Dr. Vladimir Pavlov, International Software and Productivity Engineering
Institute, USA
* Dr. Jinfeng Huang, Philips & LiteOn Digital Solutions Netherlands,
Advanced Research Centre,
The Netherlands
* Dr. Thierry Vallee, Georgia Southern University, Statesboro, Georgia, USA
* Dr. Menouer Boubekeur, University College Cork, Ireland
* Dr. Ana Sokolova, University of Salzburg, Austria
* Dr. Sergio Almerares, STMicroelectronics, Italy
* Ajay Patel (Director), Intelligent Support Ltd, United Kingdom
* Monica Donno (Director), Minteos, Italy
* Alessandro Carlo (Manager), Research and Development Centre of FIAT, Italy
* Yui Fai Lam (Manager), Microsystems Packaging Institute, Hong Kong
University of
   Science and Technology, Hong Kong

Important Dates
---
April 1, 2008: Deadline for submission of completed papers
May 15, 2008: Notification of acceptance/rejection to authors

Please visit our web-site for further information on the hosting conference
of DTVCS,
submission guideline

Re: Garbage collection

[Duncan Booth]

Jarek Zgoda <[EMAIL PROTECTED]> wrote:

> Duncan Booth napisa³(a):
> 
>> Pretty much. If you have a __del__ method on an object then in the
>> worst case the only thing that can be guaranteed is that it will be
>> called zero, one or more than one times. (Admittedly the last of
>> these only happens if you work at it).
>> 
>> If it is called then is may be either immediately the last reference
>> to the object is lost, or it may be later when the garbage collector
>> runs (and not necessarily the first next time the garbage collector
>> runs). 
> 
> Java finalizers are not called upon VM exit, only when object is swept
> by GC (for example when the object is destroyed upon program exit),
> the CPython docs read that this is the case for Python too. Is this
> behaviour standard for all VM implementations or is
> implementation-dependent (CPython, Jython, IronPython)?
> 
Yes, CPython does reference counting so it can call __del__ immediately 
an object is unreferenced. The GC only comes into play when there is a 
reference loop involved. If an object is directly involved in a 
reference loop then __del__ is not called for that object, but a loop 
could reference another object and its __del__ would be called when the 
loop was collected.

Other Python implementations may behave differently: presumably Jython 
works as for Java (but I don't know the details of that), and IronPython 
uses the CLR which has its own peculiarities: finalizers are all called 
on a single thread which is *not* the thread used to construct the 
object, so if you use finalizers in a CLR program your program is 
necessarily multi-threaded with all that implies. Also it takes at least 
two GC cycles to actually release memory on a CLR object with a 
finalizer, on the first cycle objects subject to finalization are simply 
added to a list (so are again referenceable), on the second cycle if the 
finalizer has completed and the object is unreferenced it can be 
collected. CLR finalizers also have the interesting quirk that before 
the finalizer is called any references the object has to other objects 
are cleared: that allows the system to call finalizers in any order.

Otherwise I think the behaviour on exit is pretty standard. If I 
remember correctly there is a final garbage collection to give 
finalizers a chance to run. Any objects which become newly unreferenced 
as a result of that garbage collection will have __del__ called as 
usual, but any which merely become unreachable and therefore would be 
caught in a subsequent garbage collection won't.
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Re: The big shots

[Bruno Desthuilliers]

Diez B. Roggisch a écrit :
> [EMAIL PROTECTED] schrieb:
>> I'm a little dissatisfied, and just thinking aloud.
(snip remaining of mostly inarticulate post, just couldn't make sens of 
it - as usual)

> No idea what's wrong with these people here - but I bet if you team up 
> with Illias, you can start working on his language-to-rule-them-all in 
> no time, shortening the delivery goal of 2011 immensly.

Hum... Perhaps a bit harsh, but there's something here : castironpi's 
posts definitively have something in common with Illias' ones. Couldn't 
name exactly what, but still...


If you really hope to get any serious attention, stop whining and learn 
to express yourself clearly. This won't necessarily make anybody agree 
with your proposals, but at least chances are someone will read them.

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Re: Garbage collection

[Nick Craig-Wood]

Hrvoje Niksic <[EMAIL PROTECTED]> wrote:
>  Simon Pickles <[EMAIL PROTECTED]> writes:
> 
> > Ken wrote:
> >> What is your __del__ method doing?
> >>   
> > Actually, nothing but printing a message when the object is deleted,
> > just morbid curiosity.
> >
> > I've yet to see one of the destructor messages, tho
> 
>  Do your objects participate in reference cycles?  In that case they
>  are deallocated by the cycle collector, and the cycle collector
>  doesn't invoke __del__.
> 
> >>> class X(object):
>  ...   def __del__(self): print "gone"
>  ...
> >>> a = X()
> >>> a = 1
>  gone
> >>> b = X()
> >>> b.someslot = b
> >>> b = 1
> >>> import gc
> >>> gc.collect()
>  0
> >>> 

If you want to avoid this particular problem, use a weakref.

  >>> c = X()
  >>> from weakref import proxy
  >>> c.weak_reference = proxy(c)
  >>> c.weak_reference.__del__
  >
  >>> c = 1
  >>> gc.collect()
  gone
  0
  >>>  

Or perhaps slightly more realistically, here is an example of using a
WeakKeyDictionary instead of __del__ methods for keeping an accurate
track of all classes of a given type.

from weakref import WeakKeyDictionary

class Y(object):
_registry = WeakKeyDictionary()
def __init__(self):
self._registry[self] = True
@classmethod
def list(cls):
return cls._registry.keys()

a = Y()
b = Y()
c = Y()
Y.list()
a = 1
c = 1
Y.list()

Which produces the output

[<__main__.Y object at 0xb7d9fc8c>, <__main__.Y object at 0xb7d9fcac>, 
<__main__.Y object at 0xb7d9fc2c>]
[<__main__.Y object at 0xb7d9fc8c>]

(It behaves slightly differently in the interactive interpreter for
reasons I don't understand - so save it to a file and try it!)

In fact I find most of the times I wanted __del__ can be fixed by
using a weakref.WeakValueDictionary or weakref.WeakKeyDictionary for a
much better result.

-- 
Nick Craig-Wood <[EMAIL PROTECTED]> -- http://www.craig-wood.com/nick
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Call for volunteers to help maintain bugs.python.org's issue tracker

[Brett Cannon]

The Python Software Foundation's infrastructure committee is looking
for volunteers to help maintain the Roundup issue tracker installed
for http://bugs.python.org. Responsibilities revolve around
maintaining the Roundup installation itself (tracker schema, modifying
the installed copy of Roundup, etc.) and the occasional database work
(changes to the database, etc.).

You do not have to be an expert at Roundup to volunteer! You can learn
"on the job" by doing offline development and submitting patches until
you are of a proper level of experience to gain commit access to the
code (which can be seen at XXX). If you still have a New Years
resolution to help Python out this is a great way to fulfill the
promise you made yourself for 2008!

If you are interested in volunteering, please email tracker-discuss at
python.org. Thanks to all who have helped with the tracker already and
those that will in the future!

-Brett Cannon
Chairman, PSF infrastructure committee
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Re: ANN: Phatch = PHoto bATCH processor and renamer based on PIL

[Steve Holden]

SPE - Stani's Python Editor wrote:
> I'm pleased to announce the release of Phatch which is a
> powerful batch processor and renamer. Phatch exposes a big part of the
> Python Imaging Library through an user friendly GUI. (It is using
> python-pyexiv2 to offer more extensive EXIF and IPTC support.) Phatch
> is not targeted at manipulating individual pictures (such as with
> Gimp), but repeating the same actions on hundreds or thousands of
> images.
> 
Perhaps you could put a link to the source on the Windows instalL page? 
I don't mind being a second-class citizen, but it's annoying to have to 
jump around like that.

Looks like a nice piece of work.

regards
  Steve
-- 
Steve Holden+1 571 484 6266   +1 800 494 3119
Holden Web LLC  http://www.holdenweb.com/

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Re: usage of .encode('utf-8','xmlcharrefreplace')?

[Carsten Haese]

On Mon, 18 Feb 2008 22:24:56 -0800 (PST), J Peyret wrote
> [...]
> You are right, I am confused about unicode.  Guilty as charged. 

You should read http://www.amk.ca/python/howto/unicode to clear up some of
your confusion.

> [...]
> Also doesn't help that I am not sure what encoding is used in the 
> data file that I'm using.

That is, incidentally, the direct cause of the error message below.

> [...] 
>  
> invalid byte sequence for encoding "UTF8": 0x92
> HINT:  This error can also happen if the byte sequence does not match
> the encoding expected by the server, which is controlled by
> "client_encoding".

What this error message means is that you've given the database a byte string
in an unknown encoding, but you're pretending (by default, i.e. by not telling
the database otherwise) that the string is utf-8 encoded. The database is
encountering a byte that should never appear in a valid utf-8 encoded byte
string, so it's raising this error, because your string is meaningless as
utf-8 encoded text.

This is not surprising, since you don't know the encoding of the string. Well,
now we know it's not utf-8.

> column is a varchar(2000) and the "guilty characters" are those used
> in my posting.

I doubt that. The error message is complaining about a byte with the value
0x92. That byte appeared nowhere in the string you posted, so the error
message must have been caused by a different string.

Now for the solution of your problem: If you don't care what the encoding of
your byte string is and you simply want to treat it as binary data, you should
use client_encoding "latin-1" or "iso8859_1" (they're different names for the
same thing). Since latin-1 simply maps the bytes 0 to 255 to unicode code
points 0 to 255, you can store any byte string in the database, and get the
same byte string back from the database. (The same is not true for utf-8 since
not every random string of bytes is a valid utf-8 encoded string.)

Hope this helps,

--
Carsten Haese
http://informixdb.sourceforge.net
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Re: Linux/Python Issues

[Bruno Desthuilliers]

[EMAIL PROTECTED] a écrit :
> 
> [EMAIL PROTECTED] wrote:
>> IOW: all this is assumed to be
>> common *n*x knowledge.
> 
> Both GNOME and KDE put Windows to shame. An old Windows guy, like me,
> can just start using either one without needing 'common *n*x
> knowledge.'

Err... Ever tried to compile them from sources ?-)

> Too bad the *n*x community isn't more welcoming to
> outsiders.

C'mon, Martin, be serious. Compiling softwares from sources requires at 
least some minimal 'insider' knowledge *whatever the platform*. You 
can't seriously hope each and every source distrib to provide 
newbie-oriented doc for what's obviously a power-user operation.

Or do you imply that there should be Windows installations instructions 
explaining the concepts of window, mouse, etc ? FWIW, I haven't seen so 
far any source distrib of any software targeting the Windows platform 
that didn't assume some 'common Windows knowledge'.

You label yourself as "an old Windows guy". This means you have a good 
knowledge of this platform. How long did it take to gain this knowledge 
? More than a couple weeks, I bet ?

FWIW, "a couple weeks" is the time it took me - coming from Mac then 
Windows - to be able to compile Python (or almost any other software) 
from sources on linux - and most of this time was spent solving 
dependancies issues badly managed by the particular distro I was using 
by that time, which wasn't the more standard nor documented one.

So, here's the basic scheme:

- download the source tarball, preferably in /usr/local/src
- unpack it
- cd into the unpacked source directory
- *carefully* read the README, INSTALL and other relevant docs
- run ./configure with the relevant options
- run make
- run make install

Wasn't too hard, was it ?-)

And before you say it:  yes indeed, it assumes you know how to use the 
command line, navigate your filesystem, copy/move things around, unpack 
an archive, read a text file etc... IOW, some more 'common *n*x 
knowledge' that you just can't hope to avoid learning if you want to 
properly use a *n*x system. Sorry.

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Re: Seemingly odd 'is' comparison.

[Boris Borcic]

Arnaud Delobelle wrote:
> On Feb 13, 10:19 pm, Tobiah <[EMAIL PROTECTED]> wrote:
> print float(3.0) is float(3.0)
>> True
> print float(3.0 * 1.0) is float(3.0)
>> False
> 
> [You don't need to wrap your floats in float()]
> 
 def f():
> ... return 3.0 is 3.0, 3.0*1.0 is 3.0
> ...
 f()
> (True, False)
 import dis
 dis.dis(f)
>   2   0 LOAD_CONST   1 (3.0)
>   3 LOAD_CONST   1 (3.0)
>   6 COMPARE_OP   8 (is)
>   9 LOAD_CONST   3 (3.0)
>  12 LOAD_CONST   1 (3.0)
>  15 COMPARE_OP   8 (is)
>  18 BUILD_TUPLE  2
>  21 RETURN_VALUE
> 
> As you can see when "3.0 is 3.0" is evaluated the same float object is
> put on the stack twice so the 'is' comparison is True (LOAD_CONST 1 /
> LOAD_CONST 1 / COMPARE_OP 8).
> 
> Whereas when "3.0*1.0 is 3.0" is evaluated, *two* different float
> objects are put on the stack and compared (LOAD_CONST 3 / LOAD_CONST
> 1 / COMPARE_OP 8).  Therefore the result is False.

Looks good, but doesn't pass the sanity check ;) Consider

 >>> def f():
return 3 is 3, 3*1 is 3

 >>> import dis
 >>> dis.dis(f)
   2   0 LOAD_CONST   1 (3)
   3 LOAD_CONST   1 (3)
   6 COMPARE_OP   8 (is)
   9 LOAD_CONST   3 (3)
  12 LOAD_CONST   1 (3)
  15 COMPARE_OP   8 (is)
  18 BUILD_TUPLE  2
  21 RETURN_VALUE
 >>> f()
(True, True)

Cheers, BB

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Is there a sort-of "clear" function in Pythonwin now?

[lilefei]

Looks like there are some years old questions talking about how to
clear the Pythonwin environment. But still no answer. Do we have to
close Pythonwin again and again to update our modules?
Thanks!
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Re: Garbage collection

[Duncan Booth]

Nick Craig-Wood <[EMAIL PROTECTED]> wrote:

> [<__main__.Y object at 0xb7d9fc8c>, <__main__.Y object at 0xb7d9fcac>,
> <__main__.Y object at 0xb7d9fc2c>] [<__main__.Y object at 0xb7d9fc8c>]
> 
> (It behaves slightly differently in the interactive interpreter for
> reasons I don't understand - so save it to a file and try it!)

Any expression in the interactive interpreter is implicitly assigned to 
the variable '_', so after your first call to Y.list() you've saved 
references to the complete list in _. Assignments aren't expressions so 
after assigning to a and c you haven't changed _. If you throw in 
another unrelated expression you'll be fine:

>>> a = Y()
>>> b = Y()
>>> c = Y()
>>> Y.list()
[<__main__.Y object at 0x0117F230>, <__main__.Y object at 0x0117F2B0>, 
<__main__.Y object at 0x0117F210>, <__main__.Y object at 0x0117F670>, 
<__main__.Y object at 0x0117F690>, <__main__.Y object at 0x0117F6B0>, 
<__main__.Y object at 0x0117F310>]
>>> a = 1
>>> c = 1
>>> c
1
>>> Y.list()
[<__main__.Y object at 0x0117F6B0>]

> In fact I find most of the times I wanted __del__ can be fixed by
> using a weakref.WeakValueDictionary or weakref.WeakKeyDictionary for a
> much better result.

The WeakValueDictionary is especially good when you want a Python 
wrapper round some external non-python thing, just use the address of 
the external thing as the key for the dictionary and you can avoid 
having duplicate Python objects.

The other option for classes involved in a cycle is to move the __del__ 
(and anything it needs) down to another class which isn't part of the 
cycle, so the original example becomes:

>>> class Monitor(object):
def __del__(self): print "gone"


>>> class X(object):
def __init__(self):
self._mon = Monitor()


>>> a = X()
>>> a = 1
gone
>>> b = X()
>>> b.someslot = b
>>> b = 1
>>> import gc
>>> gc.collect()
gone
8
>>> 

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Re: Call for volunteers to help maintain bugs.python.org's issue tracker

[Paul Rubin]

"Brett Cannon" <[EMAIL PROTECTED]> writes:
> The Python Software Foundation's infrastructure committee is looking
> for volunteers to help maintain the Roundup issue tracker installed
> for http://bugs.python.org. Responsibilities revolve around
> maintaining the Roundup installation itself (tracker schema, modifying
> the installed copy of Roundup, etc.) and the occasional database work
> (changes to the database, etc.).

Didn't Python.org choose the proprietary Roundup system over a free
bug tracker precisely to avoid having to do that kind of maintainance?
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Thankyou for rounding help

[katie smith]

you guys all said pretty much the same thing, use a .0 and the end or   float() 
and they all worked. Thankyou so much


  

Be a better friend, newshound, and 
know-it-all with Yahoo! Mobile.  Try it now.  
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Re: Python seems to be ignoring my except clause...

[Duncan Booth]

"Adam W." <[EMAIL PROTECTED]> wrote:

> I am trying to handle a Unicode error but its acting like the except
> clause is not even there.  Here is the offending code:
> 
> def characters(self, string):
> if self.initem:
> try:
> self.data.append(string.encode())
> except:
> self.data.append('No habla la Unicode')
> 
> And the exception:
> 
>   File "C:\Users\Adam\Desktop\XMLWorkspace.py", line 65, in characters
> try:
> UnicodeEncodeError: 'ascii' codec can't encode character u'\u2026' in
> position 83: ordinal not in range(128)
> 
> Its got to be something really dumb I'm missing, this make no sence.
> 

The example you posted isn't complete and while I can easily expand it to a 
working example it will unfortunately be a working example.

Try cutting it down yourself to a minimal self-contained example that you 
can post. 99% of the time you'll find the problem when you do that and 
avoid having to post at all.

In this case, judging by the stack backtrace quoting the wrong line, I'd 
guess you only just added the try..except and for some reason are still 
executing the old code without the exception handling.
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Re: Python seems to be ignoring my except clause...

[Szekeres István]

Hi Adam,

   def characters(self, string):
>

Please note that "string" is also a name of a very commonly used module so
it is not advised to use as a local variable name.

Istvan
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Re: File.write() not working in a sleepy loop

[Christian Heimes]

Gavin Lusby wrote:
>  write outfile 
> o=open(os.getcwd()+g.dsep+file, 'w')
> if g.verbose:
> print '...writing to '+os.getcwd()+g.dsep+file
> o.write('%over = (njobs => '+str(answer)+');\n')
> o.close
> ### sleep now #
> sleep(refresh)

Try o.close() ;)

Christian

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Re: Call for volunteers to help maintain bugs.python.org's issue tracker

[Paul Rubin]

Duncan Booth <[EMAIL PROTECTED]> writes:
> Ok, I'll bite. In what way is Roundup proprietary?

Whoops!  I was thinking of JIRA, the proprietary system (if I got it
right THAT time), that was rejected in favor of Roundup.  Sorry!!!

http://mail.python.org/pipermail/python-dev/2006-October/069139.html
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Re: Double underscores -- ugly?

[Jason]

On Feb 18, 3:28 pm, benhoyt <[EMAIL PROTECTED]> wrote:
> Hi guys,
>
> I've been using Python for some time now, and am very impressed with
> its lack of red tape and its clean syntax -- both probably due to the
> BDFL's ability to know when to say "no".
>
> Most of the things that "got me" initially have been addressed in
> recent versions of Python, or are being addressed in Python 3000. But
> it looks like the double underscores are staying as is. This is
> probably a good thing unless there are better alternatives, but ...
>
> Is it just me that thinks "__init__" is rather ugly? Not to mention
> "if __name__ == '__main__': ..."?
>
> I realise that double underscores make the language conceptually
> cleaner in many ways (because fancy syntax and operator overloading
> are just handled by methods), but they don't *look* nice.
>
> A solution could be as simple as syntactic sugar that converted to
> double underscores behind the scenes. A couple of ideas that come to
> my mind (though these have their problems too):
>
> def ~init(self):  # shows it's special, but too like a C++ destructor
> def +init(self):  # a bit too additive :-)
> defop add(self, other):  # or this, equivalent to "def __add__"
> def operator add(self, other):  # new keyword, and a bit wordy
>
> Has anyone thought about alternatives? Is there a previous discussion
> on this I can look up?
>
> Cheers,
> Ben.

Hmm.  I must be the only person who doesn't think the double
underscores are ugly.  To me, they seem to provide plenty of attention
to the special methods, but still appear clean due to their almost
white-space-like nature.  Given the use of underscores to indicate
italics in plain-text, the special methods seem (to me) to have extra
emphasis.

I don't print my code often, so that's a caveat, and I came from a C/C+
+ background.

I agree with Ben, that your suggestions don't particularly stand out.
They might stand out if the editor you used supported syntax
highlighting.  Personally, I find the examples with the plus and tilde
(+, ~) to be more noisy and ugly than the underscores.

Think of the underscores as a serene white-space day, with a simple
black road that takes you to the special name.  Or, you can wonder
what I'm smoking when I code *grin*

  --Jason
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Re: Call for volunteers to help maintain bugs.python.org's issue tracker

[Duncan Booth]

Paul Rubin  wrote:

> "Brett Cannon" <[EMAIL PROTECTED]> writes:
>> The Python Software Foundation's infrastructure committee is looking
>> for volunteers to help maintain the Roundup issue tracker installed
>> for http://bugs.python.org. Responsibilities revolve around
>> maintaining the Roundup installation itself (tracker schema, modifying
>> the installed copy of Roundup, etc.) and the occasional database work
>> (changes to the database, etc.).
> 
> Didn't Python.org choose the proprietary Roundup system over a free
> bug tracker precisely to avoid having to do that kind of maintainance?
> 

Ok, I'll bite. In what way is Roundup proprietary?

So far as I can tell it has a very unrestrictive license: maintain the 
copyright notice and otherwise do what you want, except for the parts 
derived from Zope which use the ZPL v2.0.
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Re: Python seems to be ignoring my except clause...

[Adam W.]

On Feb 19, 8:49 am, Duncan Booth <[EMAIL PROTECTED]> wrote:
> The example you posted isn't complete and while I can easily expand it to a
> working example it will unfortunately be a working example.
>
> Try cutting it down yourself to a minimal self-contained example that you
> can post. 99% of the time you'll find the problem when you do that and
> avoid having to post at all.
>
> In this case, judging by the stack backtrace quoting the wrong line, I'd
> guess you only just added the try..except and for some reason are still
> executing the old code without the exception handling.- Hide quoted text -
>
> - Show quoted text -

You hit the nail on the head with the old code, I found it funny
myself it was quoting the try statement and not the code within.  So I
deleted my .pyc files and reran, same thing, but then I closed all
open windows and reran it, and it recompiled the pyc and the code
"worked".  But now there is a new problem.  I added a print statement
to the except clause to make sure it was executing, and something
funny happen, it printed 3 times and then spat this out:

  File "C:\Users\Adam\Desktop\XMLWorkspace.py", line 72, in parsexml
parse(url, FeedHandlerInst)
  File "C:\Python25\lib\xml\sax\__init__.py", line 33, in parse
parser.parse(source)
  File "C:\Python25\lib\xml\sax\expatreader.py", line 107, in parse
xmlreader.IncrementalParser.parse(self, source)
  File "C:\Python25\lib\xml\sax\xmlreader.py", line 123, in parse
self.feed(buffer)
  File "C:\Python25\lib\xml\sax\expatreader.py", line 211, in feed
self._err_handler.fatalError(exc)
  File "C:\Python25\lib\xml\sax\handler.py", line 38, in fatalError
raise exception
SAXParseException: http://revision3.com/systm/feed/wmv-large/:78:83:
undefined entity

Huh?  Why did it not raise this BEFORE it attempted to append the
string, why did my print statment print 3 times before this error?  I
think I got past the hump I was hitting, and found a new one, 3 items
later, I will investigate.  But now I know I have to keep deleting my
pyc files or else I will run into trouble.
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Re: Double underscores -- ugly?

[Marco Mariani]

Ben Finney wrote:

>> I realise that double underscores make the language conceptually
>> cleaner in many ways (because fancy syntax and operator overloading
>> are just handled by methods), but they don't *look* nice.
> 
> That's a good thing, in that it draws attention to the names.

Well, double underscore is awful when you have to read code with the 
wrong typeface, possibly printed.
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File.write() not working in a sleepy loop

[Gavin Lusby]

Hello,

I am getting odd behaviour when I am trying to write a file in a while loop
with a sleep function call.

I am trying to periodically change the number of jobs on a cluster depending
on the current usage and a dummy version that does not require access to the
cluster usage is attached at the end.

The crux of the matter is in the main loop. When I run it, it writes a blank
file on the first iteration, then sleeps and on the 2nd iteration, it
finally puts in the correct value. I simply can't understand why it
postpones the open, write, close section of the 1st loop until the sleep is
finished. The sleep() is clearly after the write().

Thanks in advance, Gavin

 
___sample_code___sample_code___sample_code___sample_code___sample_code___sample_code___sample_code

while i == 1:
if pid <> -1:
i = pid_exists(pid)
if g.verbose: os.system('clear')
## get data ###
freeload, halfload, fullload =
20,20,40#getnodedata()<--- dummy data
weekend, phase = gettimedata()
userload =
2#getuserdata()<-- dummy
data
if g.verbose: print '...total nodes =',2 * (freeload + halfload +
fullload)
if g.verbose: print '...used nodes =',halfload + 2 * fullload
if g.verbose: print '...free nodes =',2 * freeload + halfload
if g.verbose: print '...user nodes =',userload
# usage logic #
if weekend or phase == 3:
answer = maxnode
if g.verbose:
print '...maxing out the machine with '+str(answer)
else:
answer = max(minnode,2*freeload+halfload-slack)
if g.verbose:
print '...limiting runs to '+str(answer)+' nodes'
 write outfile 
o=open(os.getcwd()+g.dsep+file, 'w')
if g.verbose:
print '...writing to '+os.getcwd()+g.dsep+file
o.write('%over = (njobs => '+str(answer)+');\n')
o.close
### sleep now #
sleep(refresh)
#! /data/gen27/utg/lusbg1/bin/Python-2.5.1/python
import sys, os, getopt, datetime
from time import sleep
from subprocess import Popen, PIPE
from getpass import getuser

class g:
'''
global variables class

'''
if os.name in ('nt','dos','ce'):
dsep = '\\'
else:
dsep = '/'
verbose = False

def main():
'''
main iterative subroutine

'''
if g.verbose: os.system('clear'); print '\n...loadmax.py'
### get opts ##
try:
opts, args = getopt.getopt(sys.argv[1:], "o:p:r:l:u:s:thv", 
["help","verbose"])
except getopt.GetoptError:
usage()
sys.exit()
file = 'mybad'
slack = 20
minnode = 40
maxnode = 100
refresh = 10*60
tracker = 'tracker.dat'
answer = 0
pid = -1
for opt, arg in opts:
if opt == "-v": # verbosity switch
g.verbose = True
if opt == "-o": # output filename switch
file = arg
if opt == "-t": # tracker filename switch
tracker = True
if opt == "-r": # refresh rate converted min->sec
refresh = float(arg)*60.0
if opt == "-u": # maximum permissable nodes
maxnode = int(arg)
if opt == "-l": # minimum permissable nodes
minnode = int(arg)
if opt == "-p": # follow specified pid
pid = int(arg)
if opt == "-s": # no of slack nodes
slack = int(arg)
if opt in ("-h", "--help"): # help!
usage()
sys.exit()
if file == 'mybad':
print '...error: output file not specified'
usage()
sys.exit()
i = 1
while i == 1:
if pid <> -1:
i = pid_exists(pid)
if g.verbose: os.system('clear')
## get data ###
freeload, halfload, fullload = 20,20,40#getnodedata()
weekend, phase = gettimedata()
userload = 2#getuserdata()
if g.verbose: print '...total nodes =',2 * (freeload + halfload + 
fullload)
if g.verbose: print '...used nodes =',halfload + 2 * fullload
if g.verbose: print '...free nodes =',2 * freeload + halfload
if g.verbose: print '...user nodes =',userload
# usage logic #
if weekend or phase == 3:
answer = maxnode
if g.verbose:
print '...maxing out the machine with '+str(answer)
else:
answer = max(minnode,2*freeload+halfload-slack)
if g.verbose:
 

[EMAIL PROTECTED]

[Matias Surdi]

test

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psycopg2: connect copy_from and copy_to

[Thomas Guettler]

Hi,

I want to copy data from a production database to
a testing database. Up to now I used psycopg2 and
copy_from and copy_to with two cursors and a temporary file.

This works, but it would be better, if the data
gets piped from one cursor to the next without a temporary
file.

The psycopg2 methods look like this:
copy_to(fd, table)   # read data
copy_from(fd, table) # write data

Using select (wait until fd has data) does not work, since
I pass in the fd. If copy_to would return the file descriptor,
I could use it to pass the data to copy_from.

I found no way to connect them. Maybe it could be done
with threading, but I try to avoid threads.

Since the script will run only on Unix, I could use pipes. But
this would fail, too, since copy_to() would block before I can
call copy_from (since buffer is full and no one is reading the data
from the pipe).

Any suggestions?

  Thomas



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[EMAIL PROTECTED]

[Matias Surdi]

test

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Re: Seemingly odd 'is' comparison.

[Duncan Booth]

Boris Borcic <[EMAIL PROTECTED]> wrote:
> Arnaud Delobelle wrote:
>> Whereas when "3.0*1.0 is 3.0" is evaluated, *two* different float
>> objects are put on the stack and compared (LOAD_CONST 3 / LOAD_CONST
>> 1 / COMPARE_OP 8).  Therefore the result is False.
> 
> Looks good, but doesn't pass the sanity check ;) Consider
> 
> >>> def f():
>  return 3 is 3, 3*1 is 3
> 
> >>> import dis
> >>> dis.dis(f)
>2   0 LOAD_CONST   1 (3)
>3 LOAD_CONST   1 (3)
>6 COMPARE_OP   8 (is)
>9 LOAD_CONST   3 (3)
>   12 LOAD_CONST   1 (3)
>   15 COMPARE_OP   8 (is)
>   18 BUILD_TUPLE  2
>   21 RETURN_VALUE
> >>> f()
> (True, True)
> 

s/different/possibly different depending on implementation details/

Arnaud's point remains valid: in the first comparison you can see that the 
same object is used, in the second case all bets are off.
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Re: Seemingly odd 'is' comparison.

[Boris Borcic]

Duncan Booth wrote:
> Boris Borcic <[EMAIL PROTECTED]> wrote:
>> Arnaud Delobelle wrote:
>>> Whereas when "3.0*1.0 is 3.0" is evaluated, *two* different float
>>> objects are put on the stack and compared (LOAD_CONST 3 / LOAD_CONST
>>> 1 / COMPARE_OP 8).  Therefore the result is False.
>> Looks good, but doesn't pass the sanity check ;) Consider
>>
> def f():
>>  return 3 is 3, 3*1 is 3
>>
> import dis
> dis.dis(f)
>>2   0 LOAD_CONST   1 (3)
>>3 LOAD_CONST   1 (3)
>>6 COMPARE_OP   8 (is)
>>9 LOAD_CONST   3 (3)
>>   12 LOAD_CONST   1 (3)
>>   15 COMPARE_OP   8 (is)
>>   18 BUILD_TUPLE  2
>>   21 RETURN_VALUE
> f()
>> (True, True)
>>
> 
> s/different/possibly different depending on implementation details/

"0 substitutions made", but whatever

s/on implementation details/on further implementations details/

> Arnaud's point remains valid: in the first comparison you can see that the 
> same object is used, in the second case all bets are off.

Sure, but the issue was to explain the strangeness that

(3.0 is 3.0)!=(3.0*1.0 is 3.0)

and I just pointed out - without drawing any conclusion - that a structurally 
identical explanation would "explain" the contrafactual (3 is 3)!=(3*1 is 3).

Best, BB

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Re: SOAP strategies

[Paul Watson]

On Sat, 2008-02-16 at 10:59 -0600, Paul Watson wrote:
> What are the reasonable current day choices and best bets for the future
> when doing SOAP programming in Python?  SOAP batteries do not appear to
> be in the standard Python distribution.
> 
> Most of the SOAP related information I have been able to find on the web
> is from 2001-2002.  I am not sure if some packages are still maintained.
> Most of this is old news.
> 
> http://soapy.sourceforge.net/
> http://pywebsvcs.sourceforge.net/ (SOAPpy)
>and what is the relation of this to ZSI
> 
> http://www.intertwingly.net/stories/2002/12/20/sbe.html
> http://www.ibm.com/developerworks/library/ws-pyth5/
> http://www.opensourcetutorials.com/tutorials/Server-Side-Coding/Python/python-soap-libraries/page1.html
> 
> http://www.gossamer-threads.com/lists/python/python/619251  This is
> current, but is this a long term strategy or a short term tactic?

Have I offended?  My apologies if I have.  I thought I showed that I had
done some homework and used Google and did the other things to show that
I was willing to put forth some effort.  Please tell me if I have missed
something.  If I should look somewhere besides Python for doing SOAP,
then please say that also.  Thanks.

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Re: Seemingly odd 'is' comparison.

[Paul Rubin]

Christian Heimes <[EMAIL PROTECTED]> writes:
> >>> id(2000)
> 3084440752
> >>> id(2001)
> 3084440752

Python 2.4.4 (#1, Oct 23 2006, 13:58:00) 
>>> id(2000)
155211416
>>> id(2001)
155211416
>>> id(2000) == id(2001)
False

>From the docs:

id( object) Return the ``identity'' of an object. This is an integer
(or long integer) which is guaranteed to be unique and constant
for this object during its lifetime. Two objects with
non-overlapping lifetimes may have the same id()
value. (Implementation note: this is the address of the object.)

What has happened is 

  >>> id(2000)

allocates a memory cell and puts 2000 in it, prints out the id, then
deallocates the cell.  id(2001) then re-uses the same cell.  With the
equality comparison, both cells are alive at the same time, so the
uniqueness requirement guarantees that their id's are unequal.

A Python implementation with a compacting garbage collector might
choose not to store a unique id in any object, unless you actually
call the id function and remember the value.  So, calling id(x) could
end up costing some cpu time and memory by permanently attaching an id
number to x.
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Re: psycopg2: connect copy_from and copy_to

[Chris]

On Feb 19, 6:23 pm, Thomas Guettler <[EMAIL PROTECTED]> wrote:
> > Doesn't PostGres come with Export/Import apps ? That would be easiest
> > (and faster).
>
> Yes, you can use "pg_dump production ... | psql testdb", but
> this can lead to dead locks, if you call this during
> a python script which is in the middle of a transaction. The python
> script locks a table, so that psql can't write to it.
>
> I don't think calling pg_dump and psql/pg_restore is faster.
>
> > prod_cursor.execute('select data from production')
> > for each_record in cursor.fetchall():
> > dev_cursor.execute('insert into testing')
>
> I know, but COPY is much faster.
>
>  Thomas

I'm used to Oracle which doesn't exhibit this problem... ;)
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Re: Double underscores -- ugly?

[Hyuga]

On Feb 19, 4:01 am, Duncan Booth <[EMAIL PROTECTED]> wrote:
> Berwyn <[EMAIL PROTECTED]> wrote:
> >> Is it just me that thinks "__init__" is rather ugly? Not to mention
> >> "if __name__ == '__main__': ..."?
>
> > That ugliness has long been my biggest bugbear with python, too.  The
> > __name__ == '__main__' thing is something I always have to look up,
> > every time I use it, too ... awkward.
>
> > I'd settle for:
>
> > hidden def init(self):  # which could be extended to work
> > for everything "hidden x=3"
> > ...
>
> > And for __name__ == '__main__' how about:
>
> > if sys.main():
> > ...
>
> Or even:
>
>   @hidden
>   def init(self): ...
>
> @main
> def mymainfunc():
>...
>

I'd much rather type a few underscores than have to constantly use
decorators.  I don't see what's so ugly about __init__.  To me it just
looks like it's underscored, though maybe that comes from having
worked with a lot of wikis.  But I really don't find it an
encumbrance, and the fact that it requires no special handling from
the parser is just part of the beautiful simplicity of Python.

Hyuga
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Re: ANN: Phatch = PHoto bATCH processor and renamer based on PIL

[Fred Pacquier]

Steve Holden <[EMAIL PROTECTED]> said :

> Perhaps you could put a link to the source on the Windows instalL page? 
> I don't mind being a second-class citizen, but it's annoying to have to 
> jump around like that.

I'm interested too, and was also wondering if Phatch is as full-featured 
unders Windows as under Linux, specifically the EXIF/IPTC functions made 
available through pyexiv2 : exiv2 itself seems to discriminate between the 
two, the Windows package only has the executable, not the library.

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Re: Double underscores -- ugly?

[Wildemar Wildenburger]

Jason wrote:
> Hmm.  I must be the only person who doesn't think the double
> underscores are ugly. 
Nope. I like them too. :)

Frankly, I think it's just a matter of adaption. I too found it rather 
"ugly" in the beginning, but with anything, I've gotten used to it. (And 
I wholeheartedly support your "looks like underlined / is unintrusive 
like whitespace" argument.)

/W
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Re: Seemingly odd 'is' comparison.

[Christian Heimes]

Steven D'Aprano wrote:
> "is" is a comparison operator: it compares identity, not equality. It is 
> more or less equivalent to the expression id(x) == id(y).

Yes, the implementation of the is operator comes down to the comparison
of PyObject* pointer addresses and in CPython id() returns the address
of the PyObject*.

But it's very important to understand that "a is b" can have a different
result than "id(a) == id(b)". CPython uses all sorts of tricks to speed
up common operations. Memory allocation/de-allocation and object
creation can have a huge speed impact. Therefor Python uses free lists
to keep some empty objects around for recycling. Small integers are
cached, too.

Compare
>>> id(0)
135689168
>>> id(1)
135689184
>>> id(2)
135689200

with
>>> id(2000)
3084440752
>>> id(2001)
3084440752
>>> id(2002)
3084440752

to see the effect of small int cache vs. int free list.

Christian

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Re: psycopg2: connect copy_from and copy_to

[Chris]

On Feb 19, 5:06 pm, Thomas Guettler <[EMAIL PROTECTED]> wrote:
> Hi,
>
> I want to copy data from a production database to
> a testing database. Up to now I used psycopg2 and
> copy_from and copy_to with two cursors and a temporary file.
>
> This works, but it would be better, if the data
> gets piped from one cursor to the next without a temporary
> file.
>
> The psycopg2 methods look like this:
> copy_to(fd, table)   # read data
> copy_from(fd, table) # write data
>
> Using select (wait until fd has data) does not work, since
> I pass in the fd. If copy_to would return the file descriptor,
> I could use it to pass the data to copy_from.
>
> I found no way to connect them. Maybe it could be done
> with threading, but I try to avoid threads.
>
> Since the script will run only on Unix, I could use pipes. But
> this would fail, too, since copy_to() would block before I can
> call copy_from (since buffer is full and no one is reading the data
> from the pipe).
>
> Any suggestions?
>
>   Thomas

Doesn't PostGres come with Export/Import apps ? That would be easiest
(and faster).

Else,

prod_cursor.execute('select data from production')
for each_record in cursor.fetchall():
dev_cursor.execute('insert into testing')

that is one way of doing it
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Python seems to be ignoring my except clause...

[Adam W.]

I am trying to handle a Unicode error but its acting like the except
clause is not even there.  Here is the offending code:

def characters(self, string):
if self.initem:
try:
self.data.append(string.encode())
except:
self.data.append('No habla la Unicode')

And the exception:

  File "C:\Users\Adam\Desktop\XMLWorkspace.py", line 65, in characters
try:
UnicodeEncodeError: 'ascii' codec can't encode character u'\u2026' in
position 83: ordinal not in range(128)

Its got to be something really dumb I'm missing, this make no sence.
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Re: psycopg2: connect copy_from and copy_to

[Thomas Guettler]

> Doesn't PostGres come with Export/Import apps ? That would be easiest
> (and faster).

Yes, you can use "pg_dump production ... | psql testdb", but
this can lead to dead locks, if you call this during
a python script which is in the middle of a transaction. The python
script locks a table, so that psql can't write to it.

I don't think calling pg_dump and psql/pg_restore is faster.

> prod_cursor.execute('select data from production')
> for each_record in cursor.fetchall():
> dev_cursor.execute('insert into testing')

I know, but COPY is much faster.

 Thomas
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Re: Seemingly odd 'is' comparison.

[Christian Heimes]

Asun Friere wrote:
> So was that a yes or no?  I mean is it even possible for the identity
> behaviour of mutables to vary between implementations?  I can't see
> how they can possibly be interned, but is there some other factor I'm
> missing in regard to identity behaviour which could in fact vary
> between implementations?

In CPython some strings are interned (see the intern builtin). The free
list of lists, tuples, dict and the block allocation of ints and floats
can have  an interning like effect, too.

IronPython and Jython may not have interning or free list at all. Even
in CPython the interning and free lists are an implementation detail
that may chance between releases. In a matter of fact I'm messing around
with free lists to speed up Python 2.6/3.0 and to give back memory earlier.

Christian

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Re: Linux/Python Issues

[Sion Arrowsmith]

 <[EMAIL PROTECTED]> wrote:
>CNR, which is now free, is absolutely marvelous when it's got what you
>need. If Python2.5 were in the warehouse, I'd have clicked, gone to
>make a cup of coffee and the appropriate icon would be on my desktop
>when I came back. If I were Python.org I'd not consider anything ready
>for release until it was in the warehouse.

Er, so how is it supposed to get into the warehouse if it's not
first released from python.org ?

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-- Arthur C. Clarke
   her nu becomeþ se bera eadward ofdun hlæddre heafdes bæce bump bump bump
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Re: Linux/Python Issues

[Bjoern Schliessmann]

[EMAIL PROTECTED] wrote:

> CNR, which is now free, is absolutely marvelous when it's got what
> you need. If Python2.5 were in the warehouse, I'd have clicked,
> gone to make a cup of coffee and the appropriate icon would be on
> my desktop when I came back. 

Why don't you switch to a distribution which offers Python 2.5
binaries? All major ones do (from Debian and Ubuntu I know it for
sure). And there's no time for coffee unless you've got a /really/
slow computer.

> If I were Python.org I'd not consider anything ready for release
> until it was in the warehouse. 

Sorry, the "python.org warehouse" only offers construction sets. If
you "order" it, you'll have to build it yourself the same way you
would build all other kits. This requires a bit of knowledge and
experience.

So why not use a distribution that doesn't force the users to build
recent software but do it themselves for their users?

Regards,


Björn

-- 
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We need a licensed electrician to replace the light bulbs in the
computer room.

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Re: Encrypting a short string?

[Brian]

Hi Erik,

I really don't recommend the ROT13 cipher, as this is extremely easy to 
crack.  Most grade school kids could break this one in seconds.  ;-)

If the project that you are working upon has low security needs, (in 
other words, it's not a financial institution), than you might try 
something quite basic such as a Vigenere, transposition, or even a 
playfair.  These encryption methodologies are not secure and can be 
cracked by hackers.  Yet, for the average Joe, it will keep them away 
from the information / data stored inside.

One thing that seems to work well is to use to ciphers together.  For 
example, encrypt the data using the playfair cipher -- and then run a 
transposition cipher.  This will erase most of the "data signatures" 
that are needed for most hackers to crack the code.  At this point, 
brute force is what most people have to resort upon -- and it's mostly 
"governments" that have this ability.  ;-)

Best wishes!

Dusty
---


Bjoern Schliessmann wrote:
> Lie wrote:
> 
>> There is a simple encryption, called ROT13 (Rotate 13). This is
>> very unsecure for any cryptographical purpose, 
> 
> For enhanced security use TROT13 (triple ROT13).
> 
>> but enough to make uninformed user to think it's just a random
>> piece of letters. 
> 
> Security by obscurity doesn't work. If it needs to be protected,
> protect it well. If it doesn't need to, you don't need to obscure
> it at all.
> 
> Regards,
> 
> 
> Björn
> 
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Re: Linux/Python Issues

[Bjoern Schliessmann]

[EMAIL PROTECTED] wrote:

> Both GNOME and KDE put Windows to shame. An old Windows guy, like
> me, can just start using either one without needing 'common *n*x
> knowledge.' 

Sure, go and compile them from the sources. The X server too, please
(I got half insane from that once).

> Too bad the *n*x community isn't more welcoming to outsiders.

I think the automobile community could be more welcoming to
outsiders either. I just can refill fuel and perhaps change motor
oil, but assembling a car from its components is too hard for me.
Evil automobilers, why do they make it so complicated! 8)

Regards,


Björn

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Plasma conduit breach

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Re: psycopg2: connect copy_from and copy_to

[james . pye]

> Doesn't PostGres come with Export/Import apps ? That would be easiest
> (and faster).

Yes, PostgreSQL core has import/export apps, but they tend to target
general administration rather than transactional loading/moving of
data. ie, dump and restore a database or schema. There is a pgfoundry
project called pgloader that appears to be targeting a more general
scenario of, well, loading data, but I imagine most people end up
writing custom ETL for data flow.

> Else,
>
> prod_cursor.execute('select data from production')
> for each_record in cursor.fetchall():
>     dev_cursor.execute('insert into testing')
>
> that is one way of doing it

In any high volume cases you don't want to do that. The current best
practice for loading data into an existing PostgreSQL database is
create temp, load into temp using COPY, merge from temp into
destination(the last part is actually the tricky one ;).
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Re: psycopg2: connect copy_from and copy_to

[james . pye]

On Feb 19, 9:23 am, Thomas Guettler <[EMAIL PROTECTED]> wrote:
> Yes, you can use "pg_dump production ... | psql testdb", but
> this can lead to dead locks, if you call this during
> a python script which is in the middle of a transaction. The python
> script locks a table, so that psql can't write to it.

Hrm? Dead locks where? Have you considered a cooperative user lock?
Are just copying data? ie, no DDL or indexes?
What is the script doing? Updating a table with unique indexes?

> I don't think calling pg_dump and psql/pg_restore is faster.

Normally it will be. I've heard people citing cases of COPY at about a
million records per second into "nicely" configured systems.
However, if psycopg2's COPY is in C, I'd imagine it could achieve
similar speeds. psql and psycopg2 both being libpq based are bound to
have similar capabilities assuming the avoidance of interpreted Python
code in feeding the data to libpq.

> I know, but COPY is much faster.

yessir.
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Re: psycopg2: connect copy_from and copy_to

[james . pye]

On Feb 19, 8:06 am, Thomas Guettler <[EMAIL PROTECTED]> wrote:
> Any suggestions?

If you don't mind trying out some beta quality software, you can try
my pg_proboscis driver. It has a DBAPI2 interface, but for you to use
COPY, you'll need to use the GreenTrunk interface:

import postgresql.interface.proboscis.dbapi2 as db
# yeah, it doesn't use libpq, so you'll need to "spell" everything
out. And, no dsn either, just keywords.
src = db.connect(user = 'pgsql', host = 'localhost', port = 5432,
database = 'src')
dst = db.connect(suer = 'pgsql', host = 'localhost', port = 5432,
database = 'dst')

fromq = src.greentrunk.Query("COPY tabl TO STDOUT")
toq = dst.greentrunk.Query("COPY tabl FROM STDIN")

toq(fromq())


It's mostly pure-python, so if you don't have any indexes on the
target table, you'll probably only get about 100,000 - 150,000 records
per second(of course, it depends on how beefy your CPU is). With
indexes on a large destination table, I don't imagine the pure Python
COPY being the bottleneck.

$ easy_install pg_proboscis

Notably, it currently(version 0.9) uses the qmark paramstyle, but I
plan to make 1.0 much more psyco. =)
[python.projects.postgresql.org, some of the docs are outdated atm due
to a recent fury of development =]
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python-ldap for plone 3 (python 2.4.4)

[Erol Robaina Cepero]

Hi friend!!
I need download python-ldap for my plone 3.0.5 that use python 2.4.4.

Do you know where I can find it?

bye


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Re: Py_Finalize ERROR!

[james . pye]

On Feb 19, 12:11 am, zaley <[EMAIL PROTECTED]> wrote:
> Py_Finalize ERROR!
>
> In my C++ program ,python is embeded . I create one win thread to run
> embedded Python code .
> So at the begin of thread function I call "Py_Initialize" and at the
> end of thread function call "Py_Finalize" .
> But after I began thread several times,the program crashed  in
> function  "Py_Finalize".
> I can see the error occured at function "PyObject_ClearWeakRefs" when
> "Py_Finalize" called "type_dealloc";
>
> Note: the python25.dll(lib) is builded by VC6(SP6)

I think I ran into this error with my pgsql PL project--at some point.
I think I "fixed" it by *not* calling Py_Finalize(). =)

However, I'm sure a report would be welcome, so if you don't mind
going through some hassle, I'd suggest making a trip to the bug
tracker.
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Re: average of PIL images

[vaneric]

>
> a) Work with the 3 components in parallel (that is, use 3 separate
> matrices, one for each component, and regenerate the image at the
> end).

that wd be ok for image generation ..but to calculate covariance
matrix from the set of images i don't know if  it wd work

 eric
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Re: python-ldap for plone 3 (python 2.4.4)

[Michael Ströder]

Erol Robaina Cepero wrote:
> I need download python-ldap for my plone 3.0.5 that use python 2.4.4.
> 
> Do you know where I can find it?

http://python-ldap.sourceforge.net/download.shtml

Ciao, Michael.
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Re: SOAP strategies

[Paul Boddie]

On 19 Feb, 16:59, Paul Watson <[EMAIL PROTECTED]> wrote:
>
> Have I offended?  My apologies if I have.  I thought I showed that I had
> done some homework and used Google and did the other things to show that
> I was willing to put forth some effort.  Please tell me if I have missed
> something.  If I should look somewhere besides Python for doing SOAP,
> then please say that also.  Thanks.

There's a Wiki page here about Web services in Python:

http://wiki.python.org/moin/WebServices

I don't think that there's been a great deal of visible activity
around SOAP in the Python community other than that you've already
noticed. I entertained the idea of doing some more complete SOAP
support as an add-on to the libxml2dom project, but not wanting to
implement all the related specifications (schemas, service
descriptions), I struggle to see the benefit compared to simpler
solutions.

That's not to say that SOAP has no value. Clearly, if you consider the
different "use cases", SOAP is probably more appropriate for some than
other solutions would be. If one were exposing some kind of repository
through some kind of Web service, I'd consider approaches like REST,
along with technologies like WebDAV (which overlaps with REST), XML-
RPC and SOAP. But if the Web service were to involve issuing
relatively complicated queries, and/or the repository wasn't strictly
hierarchical (or couldn't be elegantly represented in such a way),
then it would arguably be less appropriate to deploy a "pure" REST
solution, favouring XML-RPC and SOAP instead.

What undermines SOAP for me is that if I'm not too interested in
treating it like some kind of RPC mechanism, then I can get most of
the pertinent benefits from exchanging plain XML documents. You can,
of course, do SOAP like this, but the obligation to look after the
boilerplate elements (which should permit lots of fancy features like
"routing", if such stuff is actually used in the real world) seems
like a distraction to me.

Paul
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Re: Threading the Python interpreter

[Douglas Wells]

In article <[EMAIL PROTECTED]>,
  Nick Stinemates <[EMAIL PROTECTED]> writes:
> MooJoo wrote:
> > Since I'm running each python instance in a new process, I don't believe 
> > that there is a problem and, in my testing so far, I haven't encountered 
> > anything that would lead me to believe there is a potential time bomb 
> > here. Am I correct in my assumption this is OK or just lucky so far?
> >   
> FYI -- That's not multi threading that's multiprocessing. You're safe.

Actually that's multiprogramming (or less commonly multitasking).
It's a common confusion, but in the literature, multiprocessing
means the use of multiple processors (often via "multiple cores"
in todays desktop systems).

Unfortunately for the cause of language regularity, the terms
developed separately in somewhat different communities.  The term
multiprocessing evolved in the early 1960s associated with a
hardware manufacturer of multiprocessor systems.  The term process
evolved in the mid 1960s associated with the academic community.
And the term multiprogramming evolved in the late 1960s.  All three
terms were eventually accepted by the larger computing community
with little change in their original meanings.

But, the OP should still be safe.

 - dmw

-- 
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.   Internet:  -sp9804- -at - contek.com- .
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Re: ANN: Phatch = PHoto bATCH processor and renamer based on PIL

[Daniel Fetchinson]

> > > I'm pleased to announce the release of Phatch which is a
> > > powerful batch processor and renamer. Phatch exposes a big part of the
> > > Python Imaging Library through an user friendly GUI. (It is using
> > > python-pyexiv2 to offer more extensive EXIF and IPTC support.) Phatch
> > > is not targeted at manipulating individual pictures (such as with
> > > Gimp), but repeating the same actions on hundreds or thousands of
> > > images.
> >
> > > If you know PIL and have some nice recipes laying around, it is very
> > > easy to write plugins as Phatch generates the corresponding GUI
> > > automagically just like in Django. Any existings PIL scripts can be
> > > added very easily. Let me know if you want to contribute or have any
> > > questions.
> >
> > > Homepage:http://photobatch.stani.be(free download link below)
> > > Tutorials:http://photobatch.wikidot.com/tutorials
> > >
> Translations:https://translations.launchpad.net/phatch/trunk/+pots/phatch
> > > License: GPLv3
> > > Screenshot:
> > >http://photobatch.wikidot.com/local--files/start/Screenshot-Phatch3d.jpg
> > > (the perspective and reflection is produced by Phatch itself)
>
> > This is pretty cool! I have one question about the equally cool
> > website: what tool did you use for creating this image:
> >
> > http://photobatch.wikidot.com/local--files/start/Screenshot-Phatch3d.jpg
> This is Phatchs own dogfood. I guess you missed the tutorials link.
> There is a tutorial how you can achieve this effect:
> http://photobatch.wikidot.com/tutorial-round-3d-reflect
>
> I run Phatch on three screenshots I have to put them in perspective
> with rounded corners and perspective. I let Phatch save them as a png
> so transparency is preserved. Afterwards I opened Gimp and put the
> three together on the background of a radial gradient.
>
> Let me know if it works for you.

Yep, I indeed missed the tutorial :)
Now it's clear, thanks a lot!

Cheers,
Daniel
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Re: Seemingly odd 'is' comparison.

[Arnaud Delobelle]

On Feb 19, 1:47 pm, Boris Borcic <[EMAIL PROTECTED]> wrote:
> Arnaud Delobelle wrote:
> > On Feb 13, 10:19 pm, Tobiah <[EMAIL PROTECTED]> wrote:
> > print float(3.0) is float(3.0)
> >> True
> > print float(3.0 * 1.0) is float(3.0)
> >> False
>
> > [You don't need to wrap your floats in float()]
>
>  def f():
> > ...     return 3.0 is 3.0, 3.0*1.0 is 3.0
> > ...
>  f()
> > (True, False)
>  import dis
>  dis.dis(f)
> >   2           0 LOAD_CONST               1 (3.0)
> >               3 LOAD_CONST               1 (3.0)
> >               6 COMPARE_OP               8 (is)
> >               9 LOAD_CONST               3 (3.0)
> >              12 LOAD_CONST               1 (3.0)
> >              15 COMPARE_OP               8 (is)
> >              18 BUILD_TUPLE              2
> >              21 RETURN_VALUE
>
> > As you can see when "3.0 is 3.0" is evaluated the same float object is
> > put on the stack twice so the 'is' comparison is True (LOAD_CONST 1 /
> > LOAD_CONST 1 / COMPARE_OP 8).
>
> > Whereas when "3.0*1.0 is 3.0" is evaluated, *two* different float
> > objects are put on the stack and compared (LOAD_CONST 3 / LOAD_CONST
> > 1 / COMPARE_OP 8).  Therefore the result is False.
>
> Looks good, but doesn't pass the sanity check ;) Consider
>
>  >>> def f():
>         return 3 is 3, 3*1 is 3
>
>  >>> import dis
>  >>> dis.dis(f)
>    2           0 LOAD_CONST               1 (3)
>                3 LOAD_CONST               1 (3)
>                6 COMPARE_OP               8 (is)
>                9 LOAD_CONST               3 (3)
>               12 LOAD_CONST               1 (3)
>               15 COMPARE_OP               8 (is)
>               18 BUILD_TUPLE              2
>               21 RETURN_VALUE
>  >>> f()
> (True, True)
>
> Cheers, BB

Looks good, but doesn't pass the sanity check ;) Consider:

>>> def f():
... return 100 is 100, 100*1 is 100
...
>>> f()
(True, False)
>>> dis.dis(f)
  2   0 LOAD_CONST   1 (100)
  3 LOAD_CONST   1 (100)
  6 COMPARE_OP   8 (is)
  9 LOAD_CONST   3 (100)
 12 LOAD_CONST   1 (100)
 15 COMPARE_OP   8 (is)
 18 BUILD_TUPLE  2
 21 RETURN_VALUE

Small integers are special because they are interned, that's why you
got True for the second comparison.  With a larger integer that
doesn't happen.

--
Arnaud

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Re: problem with mod_python

[Joshua Kugler]

Pradnyesh Sawant wrote:

> Hello,
> I have a small program which does 'import hashlib'. This program runs fine
> with python2.5. But when I try running the same program through
> mod_python, I get the error: 'ImportError: No module named hashlib' in the
> apache2 error.log
> 
> Searching online suggested me to include md5.so or md5module.so in
> apache2. but I don't see that in a package for debian lenny (the system
> I'm using).
> 
> So, my Q is, is it possible to make mod_python use the same PYTHONPATH as
> the python2.5 interpreter? if so, how?

It sounds like your mod_python may be compiled against a different version
of Python than your main installation?  How did you install mod_python? How
did you install your main python installation?

What is the output of the command:

ldd /path/to/mod_python.so

(the full path on my system is /usr/lib/apache2/mod_python.so)

There should be a line something like:

libpython2.5.so.1.0 => /usr/lib/libpython2.5.so.1.0 (0xb7e37000)

If it is pointing to libpython.2.4.so.1.0, then that could be the reason for
you troubles.

Hope that helps.

j

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Re: Py_Finalize ERROR!

[Gabriel Genellina]

On 19 feb, 05:11, zaley <[EMAIL PROTECTED]> wrote:
> Py_Finalize ERROR!
>
> In my C++ program ,python is embeded . I create one win thread to run
> embedded Python code .
> So at the begin of thread function I call "Py_Initialize" and at the
> end of thread function call "Py_Finalize" .
> But after I began thread several times,the program crashed  in
> function  "Py_Finalize".
> I can see the error occured at function "PyObject_ClearWeakRefs" when
> "Py_Finalize" called "type_dealloc";
>
> Note: the python25.dll(lib) is builded by VC6(SP6)

Try to not call repeatedly Py_Initialize/Py_Finalize, only at the
start/end of your program. If only one thread is running Python at the
same time I *think* you don't have to do any special handling.

--
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Re: Why must implementing Python be hard unlike Scheme?

[[EMAIL PROTECTED]]

http://codespeak.net/pypy/dist/pypy/doc/getting-started.html#what-is-...
>
> George


I'm very excited about PyPy.  It would still be nice to see a
nice succinct list of major design principles of Python
implementations somewhere.

chris
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firefox cache & Python

[subeen]

Hi,

I have got into an interesting problem. Today I found that if I type
"about:cache?device=disk" (without the quotes) in the address bar of
firefox, it displays disk cache information. Now I am thinking to
write a Python program that will read this cache info. My initial idea
is to somehow save the page in a file and parse it. But how to save
the page without human intervention (pressing ctrl+s) :) ?

Hope I could make it clear what I am trying to do...

Any clue?

regards,
Subeen.
http://love-python.blogspot.com/
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Re: Python seems to be ignoring my except clause...

[Jonathan Gardner]

On Feb 19, 6:14 am, "Adam W." <[EMAIL PROTECTED]> wrote:
> So I deleted my .pyc files and reran, same thing, but then I closed all
> open windows and reran it, and it recompiled the pyc and the code
> "worked".
> ...
> But now I know I have to keep deleting my
> pyc files or else I will run into trouble.

What editor are you using? It sounds like it doesn't set the timestamp
on the files you are editing properly. That is, every time you save
your file it should update the timestamp of the .py file so that
python can see that there is an older .pyc next to a newer .py.

But that is probably the least of your worries right now...
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Querying a complex website

[schweet1]

Greetings,

I am attempting to use python to submit a query to the following URL:

https://ramps.uspto.gov/eram/patentMaintFees.do

The page looks simple enough - it requires submitting a number into 2
form boxes and then selecting from the pull down.

However, my test scripts have been hung up, apparently due to the
several buttons on the page having the same name.  Ideally, I would
have the script use the "Get Bibligraphic Data" link.

Any assistance would be appreciated.

~Jon
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Threads vs. continuations

[miller . paul . w]

I've been doing some thinking, and I've halfway convinced myself of
the following statement: that threads as implemented by Python (or
Java) are exactly equivalent to one-shot continuations in Scheme.  Am
I right?  (I'd have asked in the scheme groups, but I feel like I'm
less likely to get flamed to death here... hehe.)

If that's the case, it seems threads plus hygeinic macros and a few
primitives a la Scheme would form a solid basis upon which to build a
programming language.  The only thing preventing Python from being
that language is the difficulty of integrating a macro system, n'est-
ce pas?

Thanks!

Paul
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Re: Using a signal to terminate a programm running with an asyncore loop

[[EMAIL PROTECTED]]

On Feb 8, 4:03 pm, Larry Bates <[EMAIL PROTECTED]> wrote:
> When signal is caught handle_shutdown_signal is called.  At that point
> SHUTDOWN_PERFORMED will ALWAYS be False.  Normally all you do in this function
> is to set SHUTDOWN_PERFORMED to True and have a test somewhere in your main
> program loop that tests if SHUTDOWN_PERFORMED:...  I know that when you reach
>
> if not SHUTDOWN_PERFORMED:
>
> SHUTDOWN_PERFORMED will always be False so #do some stuff will get executed.
>
> Setting SHUTDOWN_PERFORMED = True doesn't do any good unless you catch this 
> back
> in the main program.
>
> If I were you I would try to issue kill from console first to see if it works.
> Then try os.kill().
>
> Hope this helps some.
>
> -Larry

Sorry for the slow response.  I had other tasks come up last week that
took priority.  Got back to this today and tried it.  I simplified my
code so right now the signal handler looks like this:

def handle_shutdown_signal(signum, frame):
   print 'in shutdown handler, caught signal', signum
   asyncore.socket_map.clear()
   exit()

I'm still registering the handler the same way:

   signal.signal(signal.SIGTERM, handle_shutdown_signal)

I'm still not convinced the handler function is getting called.  I
tried killing the process from the command line (# kill -s SIGTERM
) and my print message doesn't get shown; and running ps ax shows
the program is still running.

I'm wondering if there is something else going on.  I've checked my
code and nothing else registers any signal handlers, but there are
places that use asyncore.dispatcher and asynchat to handle some
network communication; perhaps something in there re-registers the
signal handlers?

I tried writing a simple test program; running it from one shell and
killing it from another works fine:

#!/usr/bin/env python
import signal
def handler(signum, frame):
print 'caught signal', signum
exit()
signal.signal(signal.SIGTERM, handler)
while True:
a = 1
print 'out'

After I issue the fill command, I get the following output:

caught signal 15

Which is what I expected; since the handler calls exit() I didn't
expect to see the 'out' message ever get printed.

Any thoughts?

- David
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Re: C function in a Python context

[castironpi]

> #include 
> #include 

This modification required:

compilercommand='c:/programs/mingw/bin/g++'

and

strctypes= { 'i': 'int', 's': 'const char*',
 'O': 'PyObject*' }

The output is:

#include 

[ user code ]

static PyObject *
extcode_enumfactors(PyObject *self, PyObject *args) {
PyObject* result;
int arg0;
const char* arg1;
PyArg_ParseTuple(args, "is", &arg0, &arg1 );
result= enumfactors( arg0, arg1 );
return Py_BuildValue( "O", result );
}

static PyMethodDef ExtcodeMethods[] = {
{ "enumfactors", extcode_enumfactors, METH_VARARGS, "" },
{NULL, NULL, 0, NULL}
};

PyMODINIT_FUNC
initextcode(void) {
(void) Py_InitModule("extcode", ExtcodeMethods);
}

The benefits are automatic parameter parsing and automatic method
table construction.  The costs are portability and parameter parsing
flexibility.  Add up.
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Re: Threads vs. continuations

[Tim Daneliuk]

[EMAIL PROTECTED] wrote:
> I've been doing some thinking, and I've halfway convinced myself of
> the following statement: that threads as implemented by Python (or
> Java) are exactly equivalent to one-shot continuations in Scheme.  Am
> I right?  (I'd have asked in the scheme groups, but I feel like I'm
> less likely to get flamed to death here... hehe.)
> 
> If that's the case, it seems threads plus hygeinic macros and a few
> primitives a la Scheme would form a solid basis upon which to build a
> programming language.  The only thing preventing Python from being
> that language is the difficulty of integrating a macro system, n'est-
> ce pas?
> 
> Thanks!
> 
> Paul

An interesting question to which I shall stay tuned for an answer.

However, allow me to point out that there is a macro language for
Python.  It's called 'm4' ... 

-- 

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PGP Key: http://www.tundraware.com/PGP/
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Re: Passing a callable object to Thread

[castironpi]

>         The "ice-cream" example given earlier does /not/ fit the idea of a
> tuple to me; "Vanilla", "Chocolate", and "Strawberry" isn't a tuple --
> it's a list...

Flavor* flavors[]= { Vanilla, Chocolate, Strawberry };
flavorct= 3;
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Re: SOAP strategies

[Paul Watson]

On Tue, 2008-02-19 at 10:01 -0800, Paul Boddie wrote:
> On 19 Feb, 16:59, Paul Watson <[EMAIL PROTECTED]> wrote:
> >
> > Have I offended?  My apologies if I have.  I thought I showed that I had
> > done some homework and used Google and did the other things to show that
> > I was willing to put forth some effort.  Please tell me if I have missed
> > something.  If I should look somewhere besides Python for doing SOAP,
> > then please say that also.  Thanks.
> 
> There's a Wiki page here about Web services in Python:
> 
> http://wiki.python.org/moin/WebServices
> 
> I don't think that there's been a great deal of visible activity
> around SOAP in the Python community other than that you've already
> noticed. I entertained the idea of doing some more complete SOAP
> support as an add-on to the libxml2dom project, but not wanting to
> implement all the related specifications (schemas, service
> descriptions), I struggle to see the benefit compared to simpler
> solutions.
> 
> That's not to say that SOAP has no value. Clearly, if you consider the
> different "use cases", SOAP is probably more appropriate for some than
> other solutions would be. If one were exposing some kind of repository
> through some kind of Web service, I'd consider approaches like REST,
> along with technologies like WebDAV (which overlaps with REST), XML-
> RPC and SOAP. But if the Web service were to involve issuing
> relatively complicated queries, and/or the repository wasn't strictly
> hierarchical (or couldn't be elegantly represented in such a way),
> then it would arguably be less appropriate to deploy a "pure" REST
> solution, favouring XML-RPC and SOAP instead.
> 
> What undermines SOAP for me is that if I'm not too interested in
> treating it like some kind of RPC mechanism, then I can get most of
> the pertinent benefits from exchanging plain XML documents. You can,
> of course, do SOAP like this, but the obligation to look after the
> boilerplate elements (which should permit lots of fancy features like
> "routing", if such stuff is actually used in the real world) seems
> like a distraction to me.
> 
> Paul

Many thanks for your comments.  I will take a look at the site.

My primary orientation is in accessing large (one or more terabyte)
databases and doing data integration (ETL, ELT, EAI, EII) work.  Any
other suggestions?

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Re: ANN: Phatch = PHoto bATCH processor and renamer based on PIL

[Wolfgang Strobl]

"SPE - Stani's Python Editor" <[EMAIL PROTECTED]>:

>I develop Phatch on Ubuntu/Linux, but I have tested and polished it
>regularly on Windows and Mac Os X. (Only the droplet functionality
>needs to be ported.) Phatch is submitted to Debian unstable and
>Ubuntu Hardy. Packagers for other platforms are welcome.
>
>Requirements:
>- PIL 1.1.5 or higher
>- wxPython 2.6 or higher
>- pyexiv2 (optional)
>- python nautilus bindings (optional)

Hm. I just gave it a try on Windows, but in vain. See below.

C:\build\phatch-0.1.bzr385>python setup.py install

just says

Sorry your platform is not yet supported.

>>> from PIL import Image
>>> Image.VERSION
'1.1.5'
>>> import wx
>>> wx.__version__
'2.8.7.1'

By greping for "Sorry you platform", I found config.py and there
(abbreviated) the following function:

def check_config_paths(config_paths):
if config_paths: return config_paths
p   = sys.prefix
if sys.platform[:5] == 'linux':
return {
"PHATCH_IMAGE_PATH" : 
...
}
else:
sys.stderr.write('Sorry your platform is not yet supported.\n')
sys.exit()

How is this supposed to work on Windows?

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Re: The big shots

[castironpi]

On Feb 19, 5:17 am, Bruno Desthuilliers  wrote:
> Diez B. Roggisch a écrit :> [EMAIL PROTECTED] schrieb:
> >> I'm a little dissatisfied, and just thinking aloud.
>
> (snip remaining of mostly inarticulate post, just couldn't make sens of
> it - as usual)
>
> > No idea what's wrong with these people here - but I bet if you team up
> > with Illias, you can start working on his language-to-rule-them-all in
> > no time, shortening the delivery goal of 2011 immensly.
>
> Hum... Perhaps a bit harsh, but there's something here : castironpi's
> posts definitively have something in common with Illias' ones. Couldn't
> name exactly what, but still...
>
> 
> If you really hope to get any serious attention, stop whining and learn
> to express yourself clearly. This won't necessarily make anybody agree
> with your proposals, but at least chances are someone will read them.
> 

Ok, take this one.  C is faster than Python.  It would be useful, in
certain cases, to write C.

It is possible but inconvenient, out of the way.

Date: Sat, 9 Feb 2008 11:48:51 -0800 (PST)
Subject: C function in a Python context
http://groups.google.com/group/comp.lang.python/browse_frm/thread/cd2f79dd12e81912/

A simple compile and link function.  Useful for basic cases; if you
want to get fancy, don't use it.

My suspicion is that my choices of message subjects, function names,
and variable names, is the biggest hang up.
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Re: The big shots

[Carsten Haese]

On Tue, 2008-02-19 at 12:49 -0800, [EMAIL PROTECTED] wrote: 
> Ok, take this one.  C is faster than Python.  It would be useful, in
> certain cases, to write C.
> 
> It is possible but inconvenient, out of the way.

Making that easier is a worthy goal...

> Date: Sat, 9 Feb 2008 11:48:51 -0800 (PST)
> Subject: C function in a Python context
> http://groups.google.com/group/comp.lang.python/browse_frm/thread/cd2f79dd12e81912/
> 
> A simple compile and link function.  Useful for basic cases; if you
> want to get fancy, don't use it.

...and THAT's your solution?!? That solution is more insane than clever.
I enjoy thinking outside the box as much as anybody, but requiring the
run-time environment to have a compiler so that it can compile a piece
of "inline C code" every time the program is run is absolutely
ludicrous.

> My suspicion is that my choices of message subjects, function names,
> and variable names, is the biggest hang up.

I think your biggest hangup is that you believe too much in your own
creativity. There are already viable solutions out there for integrating
C and Python: Pyrex, Cython, and ctypes come to mind.

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http://informixdb.sourceforge.net


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Re: standardization allows?

[castironpi]

On Feb 13, 4:41 pm, [EMAIL PROTECTED] wrote:
> Standardization helps avoid the readability and reliability problems
> which arise when many different individuals create their own slightly
> varying implementations, each with their own quirks and naming
> conventions.

Standardization allows RCA cables, bumpers, and 115V plugs.  The Bill
of Rights allows Huckleberry Finn.  What is the analogue of the Bill
of Rights for programmers and users, whether of programming languages
or latter-generation software?
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Re: SOAP strategies

[Paul Watson]

On Tue, 2008-02-19 at 10:01 -0800, Paul Boddie wrote:
> On 19 Feb, 16:59, Paul Watson <[EMAIL PROTECTED]> wrote:
> >
> > Have I offended?  My apologies if I have.  I thought I showed that I had
> > done some homework and used Google and did the other things to show that
> > I was willing to put forth some effort.  Please tell me if I have missed
> > something.  If I should look somewhere besides Python for doing SOAP,
> > then please say that also.  Thanks.
> 
> There's a Wiki page here about Web services in Python:
> 
> http://wiki.python.org/moin/WebServices
> 
> I don't think that there's been a great deal of visible activity
> around SOAP in the Python community other than that you've already
> noticed. I entertained the idea of doing some more complete SOAP
> support as an add-on to the libxml2dom project, but not wanting to
> implement all the related specifications (schemas, service
> descriptions), I struggle to see the benefit compared to simpler
> solutions.
> 
> That's not to say that SOAP has no value. Clearly, if you consider the
> different "use cases", SOAP is probably more appropriate for some than
> other solutions would be. If one were exposing some kind of repository
> through some kind of Web service, I'd consider approaches like REST,
> along with technologies like WebDAV (which overlaps with REST), XML-
> RPC and SOAP. But if the Web service were to involve issuing
> relatively complicated queries, and/or the repository wasn't strictly
> hierarchical (or couldn't be elegantly represented in such a way),
> then it would arguably be less appropriate to deploy a "pure" REST
> solution, favouring XML-RPC and SOAP instead.
> 
> What undermines SOAP for me is that if I'm not too interested in
> treating it like some kind of RPC mechanism, then I can get most of
> the pertinent benefits from exchanging plain XML documents. You can,
> of course, do SOAP like this, but the obligation to look after the
> boilerplate elements (which should permit lots of fancy features like
> "routing", if such stuff is actually used in the real world) seems
> like a distraction to me.
> 
> Paul

Many thanks for your comments.  I will take a look at the site.

My primary orientation is in accessing large (one or more terabyte)
databases and doing data integration (ETL, ELT, EAI, EII) work.  Any
other suggestions?

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Re: Threads vs. continuations

[Aahz]

In article <[EMAIL PROTECTED]>,
 <[EMAIL PROTECTED]> wrote:
>
>If that's the case, it seems threads plus hygeinic macros and a few
>primitives a la Scheme would form a solid basis upon which to build a
>programming language.  The only thing preventing Python from being
>that language is the difficulty of integrating a macro system, n'est-
>ce pas?

"Difficulty" as measured in Guido being less likely than the survival of
a snowball in the Sahara to ever consider anything like hygenic macros.
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"All problems in computer science can be solved by another level of 
indirection."  --Butler Lampson
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Re: The big shots

[castironpi]

On Feb 19, 3:15 pm, Carsten Haese <[EMAIL PROTECTED]> wrote:
> On Tue, 2008-02-19 at 12:49 -0800, [EMAIL PROTECTED] wrote:
> > Ok, take this one.  C is faster than Python.  It would be useful, in
> > certain cases, to write C.
>
> > It is possible but inconvenient, out of the way.
>
> Making that easier is a worthy goal...
>
> > Date: Sat, 9 Feb 2008 11:48:51 -0800 (PST)
> > Subject: C function in a Python context
> >http://groups.google.com/group/comp.lang.python/browse_frm/thread/cd2...
>
> > A simple compile and link function.  Useful for basic cases; if you
> > want to get fancy, don't use it.
>
> ...and THAT's your solution?!? That solution is more insane than clever.
> I enjoy thinking outside the box as much as anybody, but requiring the
> run-time environment to have a compiler so that it can compile a piece
> of "inline C code" every time the program is run is absolutely
> ludicrous.
>
> > My suspicion is that my choices of message subjects, function names,
> > and variable names, is the biggest hang up.
>
> I think your biggest hangup is that you believe too much in your own
> creativity. There are already viable solutions out there for integrating
> C and Python: Pyrex, Cython, and ctypes come to mind.
>
> --
> Carsten Haesehttp://informixdb.sourceforge.net

OH YEAH.  Color me absent-minded.  File under "No, they're not
compiled."

On the other hand, a number of modules are not available on all
platforms.  'extcode' is merely not available on all machines.
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Re: standardization allows?

[Gerardo Herzig]

[EMAIL PROTECTED] wrote:

>Standardization allows RCA cables, bumpers, and 115V plugs.  The Bill
>of Rights allows Huckleberry Finn.  What is the analogue of the Bill
>of Rights for programmers and users, whether of programming languages
>or latter-generation software?
>  
>
I want that drogues, man
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Re: Double underscores -- ugly?

[Ben Finney]

Marco Mariani <[EMAIL PROTECTED]> writes:

> Ben Finney wrote:
> 
> >> I realise that double underscores make the language conceptually
> >> cleaner in many ways (because fancy syntax and operator overloading
> >> are just handled by methods), but they don't *look* nice.
> >
> > That's a good thing, in that it draws attention to the names.
> 
> Well, double underscore is awful when you have to read code with the
> wrong typeface, possibly printed.

The wrong typeface can make anything awful to read. This is unrelated
to double-underscores.

The solution, therefore, is also unrelated to double-underscores:
choose an appropriate typeface.

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_o__)  Redmoon |
Ben Finney
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Re: standardization allows?

[Paul Rubin]

[EMAIL PROTECTED] writes:
> Standardization allows RCA cables, bumpers, and 115V plugs.  The Bill
> of Rights allows Huckleberry Finn.  What is the analogue of the Bill
> of Rights for programmers and users, whether of programming languages
> or latter-generation software?

http://gplv3.fsf.org   ;-)
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Re: The big shots

[castironpi]

On Feb 19, 12:37 am, George Sakkis <[EMAIL PROTECTED]> wrote:
> On Feb 19, 12:08 am, [EMAIL PROTECTED] wrote:
>
> > The problem did not seem to be miscommunication, rather bias.
>
> IMHO it's partly because of the obscurity of the ideas and the code
> you suggest, and partly because of the poor job you do to explain
> them.
>
> By the way, you may have noticed that you have been mostly replying to
> your own posts here in c.l.py, which indicates that the lack of
> responses has nothing to do with the supposed snobbishness of the "big
> shots".
>
> George

I'm going to start marking my subjective comments with a star, so it's
clear what is emperically verifiable, and what is not.

It's a bad sign.  If you aren't keeping your thoughts to yourself, and
thrashing about the world for a peer, a social network, a support
group, or a community, then you missed the day in grammar school when
they were handing out smiles.  But they're not handing them out
anymore.

Even on my emperical claims, I'm wrong 90% of the time.  On the
subjective ones, I'm not only wrong that much, but no one else want to
hear, or even can verify them.  Smell's fine to me.

Emotions are prejudiced; and even in my own concrete thoughts, I will
misidentify myself with another, and others with me.  When I say "I",
I mean "you."

French and Spanish have impersonal pronouns: "on" and "se",
respectively.  In English, they often come out as, "we", "they", and
"you" a lot, on occasion a "one", and sometimes, even, I.
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Re: What's "the standard" for code docs?

[Preston Landers]

On Feb 16, 1:56 am, John Nagle <[EMAIL PROTECTED]> wrote:
> Preston Landers wrote:
> > Hey guys and gals.  What are all the cool kids using these days to
> > document their code?
>
>HTML.  Text-only docs are so last-cen.

My sarcasometer is broken today... are you being serious?


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Re: standardization allows?

[castironpi]

On Feb 19, 4:05 pm, Paul Rubin  wrote:
> [EMAIL PROTECTED] writes:
> > Standardization allows RCA cables, bumpers, and 115V plugs.  The Bill
> > of Rights allows Huckleberry Finn.  What is the analogue of the Bill
> > of Rights for programmers and users, whether of programming languages
> > or latter-generation software?
>
> http://gplv3.fsf.org  ;-)

What are the words that everyone understands?
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Re: Threads vs. continuations

[Arnaud Delobelle]

On Feb 19, 8:26 pm, [EMAIL PROTECTED] wrote:
[...]
> The only thing preventing Python from being
> that language is the difficulty of integrating a macro system, n'est-
> ce pas?

Well there's logix (http://www.livelogix.net/logix/)


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Re: firefox cache & Python

[Gabriel Genellina]

En Tue, 19 Feb 2008 17:44:57 -0200, subeen <[EMAIL PROTECTED]>  
escribió:

> I have got into an interesting problem. Today I found that if I type
> "about:cache?device=disk" (without the quotes) in the address bar of
> firefox, it displays disk cache information. Now I am thinking to
> write a Python program that will read this cache info. My initial idea
> is to somehow save the page in a file and parse it. But how to save
> the page without human intervention (pressing ctrl+s) :) ?

Search for "firefox automation"

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