Nabble - Python - python-list

Re: Problem with Dynamically unloading a module

2009-12-24T04:51:57Z

Steven D'Aprano wrote:

> On Wed, 23 Dec 2009 15:31:53 +0100, Jean-Michel Pichavant wrote:
>
>
>> Steven D'Aprano wrote:
>>
>>> On Wed, 23 Dec 2009 13:37:06 +0100, Jean-Michel Pichavant wrote:
>>>
>>>
>>>
>>>> But believe me, you don't want to mess up with the python import
>>>> mechanism.
>>>>
>>>>
>>>>
>>> Unless you understand how it works.
>>>
>>>
>>>
>>>
>> Let me quote the OP: 'Not an expert in Python' I was just answering the
>> OP question, without refering to something he could do if he was someone
>> else.
>>
>
> But what he *can* do is to learn how importing works. I'm not sure it's
> terribly helpful to tell somebody all the things they can't do instead of
> what they can.
>
>
>

Hacking python imports would not be in the top of the list of things I
would teach to some python newcomer, that was my point.

And to be a little more constructive, let's give the OP a litle bit of help.

How can you unload module in python ?

That I don't know, anyone knows ?

JM
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Re: Regex help needed!

2009-12-24T04:35:09Z

On 21.12.2009 12:38, Oltmans wrote:

> Hello,. everyone.
>
> I've a string that looks something like
> ----
> lksjdfls<div id ='amazon_345343'> kdjff lsdfs</div> sdjfls<div id
> = "amazon_35343433">sdfsd</div><div id='amazon_8898'>welcome</div>
> ----
>
> > From above string I need the digits within the ID attribute. For
> example, required output from above string is
> - 35343433
> - 345343
> - 8898
>
> I've written this regex that's kind of working
> re.findall("\w+\s*\W+amazon_(\d+)",str)
>
> but I was just wondering that there might be a better RegEx to do that
> same thing. Can you kindly suggest a better/improved Regex. Thank you
> in advance.
>

If you filter in two or even more sequential steps the problem becomes a
lot simpler, not least because you can
test each step separately:

>>> r1 = re.compile ('<div id\D*\d+[^>]*') # Add ignore case and
variable white space
>>> r2 = re.compile ('\d+')
>>> [r2.search (item).group () for item in r1.findall (s) if item]
# s is your sample
['345343', '35343433', '8898'] # Supposing all ids have digits

Frederic

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Re: how to register with pypi - no such setup.py

2009-12-24T03:32:26Z

> Any tips?

A binary distribution won't have a setup.py, because
you can install it by other means (such as Windows Installer),
instead of running setup.py

What you want is a source distribution (sdist).

Even if you want to create a binary distribution, don't use the
bdist command, but some specialization, such as bdist_rpm.

Regards,
Martin
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Re: Object Relational Mappers are evil (a meditation)

2009-12-24T02:54:18Z

On 12/24/2009 12:11 PM, Terry Reedy wrote:
>>> This buggy idiom survived many years of Python development, missed by
>>> virtually everyone.
>
> The last statement is false. The hazard of using and/or was well-known
> back in '97 or so when I discovered or learned it and I believe it was
> mentioned in the FAQ entry on the subject. The new alternative has the
> hazard that the condition and if-branch must be written and read in a
> backwards order. I consider that buggy and do not use it for that reason.

Oh really? I thought putting the conditional in the middle was
ingenious, whoever thought that must have the next Turing award!

I always feel there's something wrong with the (condition ? true :
false) or (if condition then true else false) expressions found in other
languages; and just realized it was because of their unnatural ordering.
I have to admit initially the reversed ordering do confound me, but
afterward it felt even more natural than the traditional
"conditional-first" expression.
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Re: wave robot notes

2009-12-24T02:36:33Z

Aaron Watters <aaron.watters@...> wrote:

> I implemented a Google Wave Robot which annotates
> BNF syntax rules using railroad diagram images.
> I put notes about the implementation process
> here for the benefit of posterity.
>
> http://listtree.appspot.com/firstWaveRobot
>
> The robot Id is
>
> whiff-gae-tutorial@...
>
> -- if you are using wave, please add it to a wave and try it out.
> It should "respond" to a BNF rule you type in like this one:
>
> program ::= "begin" (statement ";")+ "end" $$
>
> Happy Holidays everyone... I'm off to the slopes :).
> -- Aaron Watters

Nice one.

Smooth curves would be nicer than angles if your graphics are up to it.

If you repeat an expression that already exists further up the Wave it
looks like the robot ignores the duplicate. Is that deliberate?

This one looks nice if you want a reasonably complex example.

import_stmt ::= "import" module ["as" name]( "," module ["as" name] )*|
"from" relative_module "import" identifier["as" name]( "," identifier
["as"name] )*| "from" relative_module "import" "("identifier ["as" name](
","identifier ["as" name] )* [","] ")"| "from" module "import" "*"

It would be really great if the diagram was interactive: I don't know if
Wave's api lets you define anchors and jumps to anchors, but if it does
then you could make non-terminals clickable.

P.S. could you use a standard signature separator please so I don't have to
trim your signature off the reply by hand?
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Re: Problem with Dynamically unloading a module

2009-12-23T19:20:32Z

lordofcode wrote:

> Hi All
>
> Not an expert in Python, so sorry if this sounds like a silly
> question.
> I went through other few threads in the mailing list but they are not
> helping me much.
> I have run into a problem related to dynamically loading and unloading
> a module.
> I need to dynamically load a module and unload it and load another
> module.
>
> For example I have many files(All files in Python are modules right?)
> like mobile_1.py ,mobile_2.py, mobile_3.py etc.. in my project folder
> which contains classes and methods with same name but different
> functionality.(am afraid I cannot change this structure as these files
> are generated randomly by the user)
>
> So initially when my program starts I have to load a default module. I
> do this as follows:
> ##############################
>>> MODULE_name = "mobile_1"
>>> exec "from "+MODULE_name+" import *"
> ##############################
> And use the methods defined in "mobile_1.py" file
>
> Now as the application continues , I may have to use the methods
> defined in "mobile_2.py" or "mobile_3.py" etc instead of the
> previously loaded module,which I incorrectly try to do as below:
> ####################
>>> MODULE_name = "mobile_2"
>>> exec "from "+MODULE_name+" import *"
> #####################
> The above import does not have any impact and the methods called from
> my application still pertain to mobile_1.py as its still in the
> current namespace(?).
> I tried below code with del(), reload() etc but could not figure it
> out.
> ###Code to unload a dll####
>>> del sys.modules[MODULE_name] #==> does not delete the reference in namespace
>
>
> 1)How do I unload a module dynamically and completely remove the
> references in the module so a new module with same name references can
> be loaded?
> 2)Are there any alternative way to do the above requirement?
> Currently I am working around by restarting the whole initial setup
> for each new module which is unnecessary waste.Can I avoid this
> "reset"?
>

I'd argue that you don't want to unload the old code before loading the
new module, and that what you really need is an understanding that if
mod1 and mod2 both define a function called f then you can perfectly
happily reference the two functions as

mod1.f

and

mod2.f

Indeed, if x is some object that needs processing by functions f, g and
h from module mod1 then it's perfectly valid to write

mod = mod1
result = mod.f(mod.g(mod.h(x)))

for example. So you can write code that uses the appropriate module for
each input.

It's possible, of course, that I am misunderstanding your requirements,
but I hope that helps.

regards
Steve
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Holden Web LLC http://www.holdenweb.com/
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Re: Threading with queues

2009-12-23T19:11:27Z

Lie Ryan wrote:

> On 12/22/2009 10:47 AM, Gib Bogle wrote:
>>> This is indented over one indentation level too much. You want it to
>>> be at the same level as the for above. Here, its at the same level
>>> with "t" -- meaning this entire loop gets repeated five times.
>>>
>>> I sorta really recommend a tab width of 4 spaces, not 2 :) At 2, its
>>> _really_ hard (especially if you're newer to Python) to see these
>>> kinds of issues and since indentation is program logic and structure
>>> in Python, that's bad... especially since your comment is indented to
>>> the right level, but the code isn't :)
>>>
>>> --S
>>
>> It turns out that this code isn't a great demo of the advantages of
>> threading, on my system anyway. The time taken to execute doesn't vary
>> much when the number of threads is set anywhere from 1 to 6.
>
> it does in mine:
>
> Elapsed Time: 7.47399997711 (with one thread)
> Elapsed Time: 1.90199995041 (with five threads)
>
> what sort of weird machine are you in?

Hmmm, interesting. I am running Windows XP on Intel quad core hardware, Q6600.
And you?
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Re: Object Relational Mappers are evil (a meditation)

2009-12-23T19:02:57Z

On Wed, 23 Dec 2009 20:11:25 -0500, Terry Reedy wrote:

>>> Instead the accepted, idiomatic Python way of writing this was to use
>>> short-circuit booleans:
>>>
>>> result = condition and x or y
>>>
>>> However this idiom is buggy! If x is a false-value (say, 0) then
>>> result gets set to y no matter what the value of condition.
>
> This is only a bug if one expects otherwise.

I'm not saying the behaviour of `a and x or y` is buggy, but that it's
use as a replacement for a ternary conditional expression is buggy; the
*idiom* is buggy, not the behaviour of and/or.

If I say "you can make perfect hard boiled eggs by putting the egg in a
glass of water in the microwave on high for eight minutes", and the egg
explodes, that's not a bug in the microwave, that's a bug in the recipe.

>>> This buggy idiom survived many years of Python development, missed by
>>> virtually everyone.
>
> The last statement is false. The hazard of using and/or was well-known
> back in '97 or so when I discovered or learned it and I believe it was
> mentioned in the FAQ entry on the subject.

We can argue about how well-known it was for somebody like Raymond
Hettinger to miss it, and for whoever did a code-review of his
application to also miss it.

> The new alternative has the
> hazard that the condition and if-branch must be written and read in a
> backwards order.

If you had asked me a couple of years ago, I would have agreed, but I've
now come to the conclusion that `x if condition else y` is not only
perfectly natural, but at least as natural as the conventional order of
`if condition then x else y` (at least for expressions, not for if
statements).

"Steven, what are you doing on Monday night?"
"Going to the movies if I can get away from work on time, otherwise
sitting at home answering questions on comp.lang.python."

--
Steven
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wave robot notes

2009-12-23T18:59:43Z

I implemented a Google Wave Robot which annotates
BNF syntax rules using railroad diagram images.
I put notes about the implementation process
here for the benefit of posterity.

http://listtree.appspot.com/firstWaveRobot

The robot Id is

whiff-gae-tutorial@...

-- if you are using wave, please add it to a wave and try it out.
It should "respond" to a BNF rule you type in like this one:

program ::= "begin" (statement ";")+ "end" $$

Happy Holidays everyone... I'm off to the slopes :).
-- Aaron Watters

===
an apple every 8 hours
will keep 3 doctors away --kliban
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Re: Problem with Dynamically unloading a module

2009-12-23T18:50:26Z

On Wed, 23 Dec 2009 15:18:10 -0800, Carl Banks wrote:

>> > # will unload mod1 assuming mod1 was the only reference to that
>> > module.
>>
>> Which is highly unlikely. Any classes or functions from the module will
>> keep the module alive.
>
> Actually, they won't. Neither classes nor functions directly reference
> their module; classes know their module only by name, and functions only
> hold references to the module's namespace, not to the module itself. So
> if any references to functions defined in the module remain, the module
> dict will stick around, but the module itself may be collected.

Hmmm... so it seems. Well spotted, thanks.

It makes sense to do it that way, as it prevents circular references
(module contains a class which contains the module which...).

--
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Re: Problem with Dynamically unloading a module

2009-12-23T18:32:15Z

Hi All,

Thanks you all for your replies ,cleared quiet a few doubts about
importing modules and namespace references .
Currently am going with static importing of all modules. But it may
not be efficient in future as the number of interchangeable modules
that I have to import may run in 30-40's.(Basically this Python code
is part of larger GSM Testing project where each module represents one
model of GSM mobile phone and this number keeps growing). So changing
the design will be a last resort.
But am trying to reduce the number of objects(classes,methods etc) in
each module so importing all 30-40 modules do not impact much.

Anyway am trying out all the mentioned tricks here and get back to you
with any doubts.

Thanks again
Ajay Baragur
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Re: Object Relational Mappers are evil (a meditation)

2009-12-23T17:11:25Z

>> Instead the accepted, idiomatic Python way of writing this was to use
>> short-circuit booleans:
>>
>> result = condition and x or y
>>
>> However this idiom is buggy! If x is a false-value (say, 0) then result
>> gets set to y no matter what the value of condition.

This is only a bug if one expects otherwise.

>> This buggy idiom survived many years of Python development, missed by
>> virtually everyone.

The last statement is false. The hazard of using and/or was well-known
back in '97 or so when I discovered or learned it and I believe it was
mentioned in the FAQ entry on the subject. The new alternative has the
hazard that the condition and if-branch must be written and read in a
backwards order. I consider that buggy and do not use it for that reason.

Terry Jan Reedy

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Re: creating ZIP files on the cheap

2009-12-23T16:21:18Z

On 12/23/2009 3:47 PM John Machin said...
>Is it
> maintainable? I.e. pretend that the next person to maintain your code
> knows where you live and owns a chainsaw.

Oooh... that's much better than the finger guillotine and annual
holiday-party finger count I normally threaten with...

Emile

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Re: creating ZIP files on the cheap

2009-12-23T15:47:47Z

On Dec 24, 7:34 am, samwyse <samw...@...> wrote:
> I've got an app that's creating Open Office docs; if you don't know,
> these are actually ZIP files with a different extension. In my case,
> like many other people, I generating from boilerplate, so only one
> component (content.xml) of my ZIP file will ever change. Instead of
> creating the entire ZIP file each time, what is the cheapest way to
> accomplish my goal? I'd kind-of like to just write the first part of
> the file as a binary blob, then write my bit, then write most of the
> table of contents as another blob, and finally write a TOC entry for
> my bit. Has anyone ever done anything like this? Thanks.

Option 1: set up a file that contains everything except the
content.xml. Then for each new file: copy the "empty" file, open the
copy with zipfile (mode 'a') and write your content.xml. This at least
is understandable and maintainable.

Option 2 (recommended): insert some timing apparatus into your script.
How much time is taken by the template stuff? Is it worth chancing
your arm on getting the "binary blob" stuff correct? Is it
maintainable? I.e. pretend that the next person to maintain your code
knows where you live and owns a chainsaw.
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RE: Ironpython experience

2009-12-23T15:28:43Z

Lev wrote:

> I'm an on and off Python developer and use it as one of the tools.
> Never for writing "full-blown" applications, but rather small, "one-of-
> a-kind" utilities. This time I needed some sort of backup and
> reporting utility, which is to be used by the members of our team
> once or twice a day. Execution time is supposed be negligible. The
> project was an ideal candidate to be implemented in Python. As
> expected the whole script was about 200 lines and was ready in a 2
> hours (the power of Python!).Then I downloaded Ironpython and
> relatively painlessly (except the absence of zlib) converted the
> Python code to Ironpython. Works fine and Ironython really is Python.
> But...
>
> The CPython 2.6 script runs 0.1 seconds, while Ironpython 2.6 runs
> about 10 seconds. The difference comes from the start-up, when all
> these numerous dlls/assemblies are loaded and JITed.
>
> Is there any way to speed up the process.

Can you give us more information about the environment you're running
in? E.g. how did you install IronPython, is this on 32-bit or 64-bit
and are you using ipy.exe or ipy64.exe?

The sweet spot to be in is on a 32-bit machine or a 64-bit machine
and using ipy.exe. You should also be using ngen'd (pre-compiled)
binaries which the MSI does for you. Combining 32-bit plus ngen
should greatly reduce startup time and typically on our test machines
it only takes a couple of seconds (http://ironpython.codeplex.com/wikipage?title=IP26FinalVsCPy26Perf&referringTitle=IronPython%20Performance).

That's still a lot worse than CPython startup time but it's much
better than 10 seconds. We also continue to work on startup time -
there's already some big improvements in our Main branch which should
be showing up in 2.6.1. Matching CPython is still a long ways off
if we ever can do it but do intend to keep on pushing on it.

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Re: Problem with Dynamically unloading a module

2009-12-23T15:18:10Z

On Dec 23, 7:40 am, Steven D'Aprano <st...@REMOVE-THIS-
cybersource.com.au> wrote:

> On Wed, 23 Dec 2009 13:37:06 +0100, Jean-Michel Pichavant wrote:
> > 3/ if you really need to unload the previous module, it's a little bit
> > tedious.
>
> > import mod1
> > del mod1
> > sys.modules['mod1'] = None
>
> Assigning sys.modules[name] to None is not the same as deleting the
> entry. None has special meaning to imports from packages, and for modules
> it is interpreted as meaning that the module doesn't exist.
>
> >>> import math
> >>> del math
> >>> sys.modules['math'] = None
> >>> import math
>
> Traceback (most recent call last):
> File "<stdin>", line 1, in <module>
> ImportError: No module named math
>
> > # will unload mod1 assuming mod1 was the only
> > reference to that module.
>
> Which is highly unlikely. Any classes or functions from the module will
> keep the module alive.

Actually, they won't. Neither classes nor functions directly
reference their module; classes know their module only by name, and
functions only hold references to the module's namespace, not to the
module itself. So if any references to functions defined in the
module remain, the module dict will stick around, but the module
itself may be collected.

> > But believe me, you don't want to mess up with the python import
> > mechanism.
>
> Unless you understand how it works.

Carl Banks
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Re: python 2.x and running shell command

2009-12-23T14:22:59Z

On Dec 23, 1:57 pm, tekion <tek...@...> wrote:

> All,
> some of the servers I have run python 2.2, which is a drag because I
> can't use subprocess module. My options that I know of is popen2
> module. However, it seems it does not have io blocking
> capabilities. So every time run a command I have open and close a
> file handle. I have command that requires interactive interaction. I
> want to be be able to perform following action:
> fout, fin = popen2.open2(cmd) #open up interactive session
> fin.write(cmd2);
> block (input)
> fout.readline()
> block output
> fin.write(cmd2)
> and so on...
>
> is this possible with popen2 or do I have to use pexpect for the job?
> Thanks.

I've never done that with subprocess, but maybe this will help:
http://www.lysator.liu.se/~astrand/popen5/

~Sean
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Re: Problem with Dynamically unloading a module

2009-12-23T14:04:53Z

On Wed, 23 Dec 2009 15:31:53 +0100, Jean-Michel Pichavant wrote:

> Steven D'Aprano wrote:
>> On Wed, 23 Dec 2009 13:37:06 +0100, Jean-Michel Pichavant wrote:
>>
>>
>>> But believe me, you don't want to mess up with the python import
>>> mechanism.
>>>
>>>
>> Unless you understand how it works.
>>
>>
>>
> Let me quote the OP: 'Not an expert in Python' I was just answering the
> OP question, without refering to something he could do if he was someone
> else.

But what he *can* do is to learn how importing works. I'm not sure it's
terribly helpful to tell somebody all the things they can't do instead of
what they can.

--
Steven
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Re: Object Relational Mappers are evil (a meditation)

2009-12-23T14:04:38Z

On Wed, 23 Dec 2009 10:55:19 -0500, J Kenneth King wrote:

> Steven D'Aprano <steve@...> writes:
>
>> On Mon, 21 Dec 2009 11:44:29 -0500, J Kenneth King wrote:
>>
>>> A programmer that
>>> lacks critical thinking is a bad programmer. The language they use
>>> has no bearing on such human facilities.
>>
>> That's nonsense, and I can demonstrate it by reference to a single
>> programming language, namely Python.
>>
>> For many years, Python had no ternary if operator:

[...]

> But did the lack of ternary encourage Raymond to become a bad
> programmer?

No, but Raymond started off in a position of being an excellent
programmer. A single buggy idiom lead him to be slightly-less excellent
than he otherwise would have been. How many buggy idioms would it take to
lead him to become a mediocre coder, if he was unable to change languages?

Because Python is generally an excellent language, the harm done by one
or two misfeatures is minor. But less excellent languages encourage
coding styles, techniques and idioms that encourage the programmer to
write poor code: either complicated, baroque, unreadable code; or slow
inefficient code; or buggy code. To avoid starting a flame war, I will
avoid mentioning PHP. *cough*

Sometimes you know what you need to do to write non-buggy code, but
because covering all the corners are just Too Damn Hard in a certain
language, you simply lower your expectations. Error checking is tedious
and hard to get right in some languages, like C and Pascal, and hence
even good programmers can miss some errors.

Different languages encourage different mind-sets in the programmer: C
encourages the coder to think at the low level of pointers and addresses,
and primarily about machine efficiency; Java encourages the use of big
object hierarchies and design patterns (it's hard to write lightweight
code in Java, so everything turns into heavyweight code); Perl encourages
cleverness and code-golf (writing a program in as few lines or characters
as possible); Haskell and Lisp encourage a heavily abstract approach that
often requires an elite coder to follow; Forth encourages you to think
like Yoda.

[...]
> Good tools make all the difference in the world, I'm not arguing that.

You appear to be arguing against that.

> Just that the tools don't use us; we use them.

Nobody said that tools use us.

> Programming in Python
> doesn't instantly make me a better programmer.

No, not instantly, but I would argue that after many years of coding in
Python you will be a better programmer than after the same number of
years of coding in PHP or Basic.

It also depends on what you mean by "better programmer". Some languages
value cleverness above all else. Python is not a language for writing
amazing, awe-inspiring hacks that work where nobody but the author can
work out why. This is why there is an Obfuscated C contest and an
Obfuscated Perl contest but no Obfuscated Python contest -- it wouldn't
be anywhere near as awe-inspiring.

So one might argue that the best C and Perl coders are better than the
best Python coders, but the average Python coder is better than the
average C and Perl coder.

(I suggest this as a hypothetical, and do not wish to defend it
scientifically.)

--
Steven
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python 2.x and running shell command

2009-12-23T13:57:28Z

All,
some of the servers I have run python 2.2, which is a drag because I
can't use subprocess module. My options that I know of is popen2
module. However, it seems it does not have io blocking
capabilities. So every time run a command I have open and close a
file handle. I have command that requires interactive interaction. I
want to be be able to perform following action:
fout, fin = popen2.open2(cmd) #open up interactive session
fin.write(cmd2);
block (input)
fout.readline()
block output
fin.write(cmd2)
and so on...

is this possible with popen2 or do I have to use pexpect for the job?
Thanks.
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Re: More On the Strange Problem

2009-12-23T13:40:21Z

On Wed, 23 Dec 2009 19:03:36 +0000, MRAB wrote:

>> if whatDo == 'insert':
>> theVal = defaultVal
>> val = defaultVal
>>
> What's the difference between theVal and val? The names don't help me!

Oh MRAB! Isn't it obvious? theVal has a leading definite article while
val doesn't!

Really MRAB, if you can't comprehend such clear and obvious code, you'll
never be a good programmer!

--
Steven
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Re: ISO all functions+methods+classes without docstring

2009-12-23T13:39:27Z

On Wed, 23 Dec 2009 21:08:02 +0000, kj wrote:

> I'm looking for a good way to get a listing of all the undocumented
> (i.e. docstring-less) functions, classes, and methods as defined in a
> (largish) library of files.
>
> What's a good way to get this information?

list_of_modules = []
for module_name in list_of_files:
list_of_modules.append( __import__(module_name) )

for module in list_of_modules:
for name in dir(module):
obj = getattr(module, name)
doc = getattr(obj, '__doc__', None)
if doc is None:
print module, name

The only complication is that dir deliberately only shows "interesting"
attributes, however that is defined. If this doesn't do what what you
want, you may prefer to write your own function. The inspect module will
probably come in handy.

--
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Re: creating ZIP files on the cheap

2009-12-23T13:19:28Z

On 12/24/2009 7:34 AM, samwyse wrote:
> I've got an app that's creating Open Office docs; if you don't know,
> these are actually ZIP files with a different extension. In my case,
> like many other people, I generating from boilerplate, so only one
> component (content.xml) of my ZIP file will ever change. Instead of
> creating the entire ZIP file each time, what is the cheapest way to
> accomplish my goal? I'd kind-of like to just write the first part of
> the file as a binary blob, then write my bit, then write most of the
> table of contents as another blob, and finally write a TOC entry for
> my bit. Has anyone ever done anything like this? Thanks.

You might want to look at solid and non-solid compression. Solid
compression writes all files in the binary as one huge block and must be
compressed/decompressed as a whole, while non-solid compression writes
the zipped file in chunks that can be decompressed individually.

I don't know if there's any way to compress/decompress/recompress as
non-solid compression from python though. Maybe others can point
something out, or maybe you can use an external zipper that understands
non-solid compression.
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strange geometry problem

2009-12-23T13:19:20Z

Hi all,
I'm doing a GUI for describing connectors and the signals attached. the system runs on
CentOS release 5.2 (FINAL) using python 2.5 and tcl/tk 8.4

I have a class Pin that contains two class attributes that are dialogs. They are built by a helper
routine as follows:
if type(Pin.clkDialog) == type(None):
Pin.clkDialog = bldTypeDlg(self.cnctr.gui.parent,
("Clock State Selector", "Choose a Default \nClock State\n\n\n\n"),
CLKVALUES, 0)
Pin.clkDialog.geometry('+%d+%d'%(400,400))
Pin.clkDialog.withdraw()

the second dialog is similar but with different strings passed in.
they are activated from one field of an instance variable dialog self.valDialog

The strange behavior is as follows:
The first time the class dialogs are activated they appear in front of but immediately go behind the
valDialog and are hidden. After moving the valDialog and using the class dialogs, subsequent activations
appear at a location that is effected by the geometry spec in the activate routine.

the activation code is
#####################################################################################
#####################################################################################
def getClkState(self, event):
Pin.clkDialog.geometry('+%d+%d'%(400,400))
rslt = Pin.clkDialog.tkraise()
resp = Pin.clkDialog.activate()

if resp == 'OK':
self.clkNominal = Pin.clkDialog.get()
self.entries[5].setentry(self.clkNominal)
self.valDisps[4].setentry( self.clkNominal )
else:
return "break"

#####################################################################################
#####################################################################################
def getLgcState(self, event):
Pin.lgcDialog.geometry('+%d+%d'%(400,400))
rslt = Pin.lgcDialog.tkraise()
resp = Pin.lgcDialog.activate()
if resp == 'OK':
self.lgcNominal = Pin.lgcDialog.get()
self.entries[5].setentry(self.lgcNominal)
self.valDisps[4].setentry( self.lgcNominal )
else:
return "break"

Any ideas on what's going on? and how to fix it?

Nick
nbuchholz@...
Day phone: (520) 318-8203
"Time is an illusion, Lunchtime doubly so" - Ford Prefect
Time is an illusion perpetrated by the manufacturers of space.

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Re: More On the Strange Problem

2009-12-23T13:13:47Z

On 12/24/2009 8:00 AM, MRAB wrote:
>
> >>> print first_twin == second_twin
> True

err... I don't think there is any situation where first_twin ==
second_twin wouldn't be considered a bug. They look similar, they act
similar, and they quack the same; though you can almost always treat
them the same they are still ultimately different person?
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ISO all functions+methods+classes without docstring

2009-12-23T13:08:02Z

I'm looking for a good way to get a listing of all the undocumented
(i.e. docstring-less) functions, classes, and methods as defined
in a (largish) library of files.

What's a good way to get this information?

TIA!

-Kynn
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Re: force non-exponential representation for Decimal?

2009-12-23T13:06:40Z

On Dec 23, 4:03 am, jh...@... wrote:

> (cc-ing the list)
>
> > > Is there a convenient way to force a decimal.Decimal representation to
> > not use exponential representation?
>
> > Which Python version are you using? For Python 2.6 (and 3.1), the
> > answer's yes. For earlier Python verions, I don't think so. In
> > Python 2.6, use new-style formatting with the 'f' modifier:
>
> > >>> '{0:f}'.format(Decimal('1e-100'))
> > '0.0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000001'
> > >>> '{0:f}'.format(Decimal('1e100'))
> > '10000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000'
>
> Unfortunately, I'm still using Python 2.4 so I can't go that way (at least not anytime soon, this is a production environment).

But you can get gmpy for Python 2.4. And then you can do:

>>> c = gmpy.mpf('2.3430000000837483727772E-19')
>>> c
mpf('2.34300000008374837278e-19')

>>> help(gmpy.fdigits)

Help on built-in function fdigits in module gmpy:

fdigits(...)
fdigits(x, base=10, digs=0, mine=0, maxe=-1, opts=0): formats x,
which is an mpf or else gets coerced to one.

Returns up to digs digits in the given base (if digs is 0, as many
digits as are available), but no more than available given x's
precision; the resulting string is formatted in fixed point
if the exponent is >=mine and <=maxe, else in exponential (the
exponent-separator is 'e' for base up to 10, else '@' -- the
exponent is always output as a signed, base-10 integer). If opts
has bit 1 set, the whole is wrapped in 'gmpy.mpf(...)', to ease
later approximate reconstruction via builtin function eval
(Or, in just mpf(...) if gmpy.set_tagoff(1) was called).

If opts has bit 2 set, then opts bit 1, mine, and maxe, are
ignored; the result is then a 2-element tuple, first element
the raw string of base-digits without formatting, second the
exponent in base as a Python int.

>>> gmpy.fdigits(c,10,30,-30,30)
'0.000000000000000000234300000008374837278'

>
> > For earlier Python versions, you can manipulate the output string as
> > you describe, or you can extract the raw components of the Decimal
> > instance (e.g. with the as_tuple() method) and construct a string
> > directly from those. You might be also be able to extract code for
> > the '{:f}' formatting from the Python 2.6 Decimal source (Lib/
> > decimal.py), but it's fairly convoluted.
>
> Thanks a lot for the hints, I'll look into that.
>
> Holger
>
> --
> GRATIS für alle GMX-Mitglieder: Die maxdome Movie-FLAT!
> Jetzt freischalten unterhttp://portal.gmx.net/de/go/maxdome01

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Re: More On the Strange Problem

2009-12-23T13:00:27Z

Victor Subervi wrote:

> On Wed, Dec 23, 2009 at 3:03 PM, MRAB <python@...
> <mailto:python@...>> wrote:
>
> Victor Subervi wrote:
>
> I've isolated the problem in the print-out at the bottom of this
> post. It occurs when these values are passed:
>
> ['LastDatePrice', 'date', '10', 'yyyy/mm/dd', None],
>
> Since this is the first datetime that is passed, it would appear
> to be associated with such values, which are processed thus:
>
> elif typeName == 'datetime':
>
> Where does the value of typeName come from?
>
> It is the descriptor of the MySQL type.
>
> print "<input type='text' width='%s' maxlength='%s'
> name='%s' value='%s' /> " \
> "<i>This field takes a datetime up to %s alphanumeric
> characters inclusive.</i>" \
> % (shortNum, str(typeNum), colName, theVal, str(typeNum))
>
> colName == 'LastDatePrice'
> typeNum = 10
>
> elif 10 < int(typeNum) < 20:
>
> If typeNum is 10 then 10 < int(typeNum) < 20 is False.
>
> Thank you for catching that! However, the code is followed by an else
> clause.
>
> shortNum = '10'
>
> Therefore...
> shortNum = '10'
>
> if whatDo == 'insert':
> theVal = defaultVal
> val = defaultVal
>
> What's the difference between theVal and val? The names don't help me!
> :-)
>
> if whatDo == 'insert':
> theVal = defaultVal
> val = defaultVal
> else:
> theVal = val
>
> Since whatDo == 'insert'...
> and
> val = 'yyyy/mm/dd'
> therefore
> theVal = None
>

[snip]

>
> If in fact the problem has to do with the None value, how can I
> easily substitute a different value? I tried:
>
> if theVal == None:
>
> The Pythonic way is to use "is" when comparing with singletons like
>
> None.
>
>
> Can you please explain by example?
>

Singleton: there is only ever one of certain objects and using "is" lets
you check for identity. For example, consider identical twins; they look
the same, but are not the same person. In programming terms you could
imagine the following scenario:

>>> print first_twin == second_twin
True
>>> print first_twin is second_twin
False

In Python by far the most common singleton is None; you should use "is"
(or "is not") when checking whether (or not) an object is actually None.
There might also be a few cases where a certain implementation of Python
might use singletons for reasons of efficiency, but they are just
optimisations in that implementation and shouldn't be relied on. The
rule is: if you're not checking for identity (and, as I said, by far the
most common use is with None), check for equality.

>
> theVal = ''
>
> but that didn't capture it.
>
> What do you mean by "didn't capture it"?
>
> The output was identical to what I originally posted.

I recommend that you write messages and values to a log file along the
path in the code you think it's following and then see whether it's
doing what you think it is and with the values you think it should have.
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Re: creating ZIP files on the cheap

2009-12-23T12:56:26Z

samwyse wrote:
> I've got an app that's creating Open Office docs; if you don't know,
> these are actually ZIP files with a different extension. In my case,
> like many other people, I generating from boilerplate, so only one
> component (content.xml) of my ZIP file will ever change. Instead of
> creating the entire ZIP file each time, what is the cheapest way to
> accomplish my goal? I'd kind-of like to just write the first part of
> the file as a binary blob, then write my bit, then write most of the
> table of contents as another blob, and finally write a TOC entry for
> my bit. Has anyone ever done anything like this? Thanks.
I think you intend on using simply the command-line infozip tool from
python system commands:
mycmd = "zip -r content.xml foo.zip"
mycmd = "zip -i your.blob foo.zip"
try:
mycmd = "zip -r content.xml foo.zip"
retcode = call(mycmd, shell=True)
mycmd = "zip -i your.blob foo.zip"
retcode = call(mycmd, shell=True)
if retcode < 0:
print >>sys.stderr, "Child was terminated by signal", -retcode
else:
print >>sys.stderr, "Child returned", retcode
except OSError, e:
print >>sys.stderr, "Execution failed:", e

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Re: Python-list Digest, Vol 75, Issue 226

2009-12-23T12:47:07Z

Gabriel Genellina wrote:

> En Tue, 22 Dec 2009 16:30:58 -0300, r0g <aioe.org@...>
> escribió:
>> Gabriel Genellina wrote:
>>> En Mon, 21 Dec 2009 16:30:13 -0300, Pulkit Agrawal
>>> <thatguypulkit@...> escribió:
>>>
>>>> I am writing a script wherein I need to merge files into existing
>>>> tar.gz
>>>> files. Currently, I am using tarfile module. I extract the tar.gz to a
>>>> tempdir and copy the new file there and re-compress all the files back
>>>> into
>>>> a tar.gz. Is there a better way to do it?
>>>
>>> Since noone answered yet: no, I don't think you can avoid to decompress
>>> and recompress those files.
>>
>> Erm, I always thought it was OK to simply cat gzipped files together...
>
> Maybe, but still I don't think this could help the OP. As I understand
> the problem, originally there were e.g.: file1, file2, file3; they were
> tarred into file123.tar and gzipped into file123.tar.gz. And now file2
> must be replaced by a newer version. It should go into the internal .tar
> file, replacing the old one; I don't see how to do that without
> decompressing it. (Ok, once the tar is decompressed one might replace
> the old file with the newer one in-place using the tar command, but this
> cannot be done with the tarfile Python module)
>

Oh I didn't see the original posting! I agree, if files within the
tarball need to be replaced (as opposed to more new files added) that
can only be done on uncompressed tar archives.

If performance is a issue and the files aren't too gargantuan it may be
best to de(and re)compress the gzips to memory/ramdisk rather than
writing it all out to disk. If the files are too large for memory but
the OP can afford a bit more storage then storing plain uncompressed
tarballs would allow use of tar's delete, replace and append
functionality. If that would take up too much space maybe they could use
plain tar on a block compressed filesystem instead.

Cheers,

Roger.
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Re: [pygtk] cannot import glib in python shell

2009-12-23T12:43:35Z

>
> I think ideally what I'm requesting is to have the mingw/python/gtk
> environments to be harmonized. I'm close. I can do the following:
> python
> import sys
> import gtk
> blah = gtk.Window(0)
> blah.show()
> , but when I do
> import glib
> ERROR!!!
> if I cd to a certain dir in glib sources, there were two .py files, but
> I didn't know where to place them in the python26 dir.
> From that dir, I can run the python shell, import glib and then it gives
> me an error about no module for gdb...so it's none stop...with regards
> to the import glib issue at present.
>
> Any help towards this would be greatly appreciated.

AFAIR there has not been a release of PyGObect on windows since the
split of functionality into the glib namespace.

I cleaned up the build stuff a while ago here;

https://bugzilla.gnome.org/show_bug.cgi?id=589671

But I no longer have a windows install. Someone else will need to update
it to HEAD and finish it off.

John

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creating ZIP files on the cheap

2009-12-23T12:34:22Z

I've got an app that's creating Open Office docs; if you don't know,
these are actually ZIP files with a different extension. In my case,
like many other people, I generating from boilerplate, so only one
component (content.xml) of my ZIP file will ever change. Instead of
creating the entire ZIP file each time, what is the cheapest way to
accomplish my goal? I'd kind-of like to just write the first part of
the file as a binary blob, then write my bit, then write most of the
table of contents as another blob, and finally write a TOC entry for
my bit. Has anyone ever done anything like this? Thanks.
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Re: More On the Strange Problem

2009-12-23T12:13:14Z

Victor Subervi wrote:

> On Wed, Dec 23, 2009 at 2:21 PM, Victor Subervi <victorsubervi@...>wrote:
>
>> I've isolated the problem in the print-out at the bottom of this post. It
>> occurs when these values are passed:
>>
>> ['LastDatePrice', 'date', '10', 'yyyy/mm/dd', None],
>>
>> Since this is the first datetime that is passed, it would appear to be
>> associated with such values, which are processed thus:
>>
>> elif typeName == 'datetime':
>> print "<input type='text' width='%s' maxlength='%s' name='%s'
>> value='%s' /> " \
>> "<i>This field takes a datetime up to %s alphanumeric characters
>> inclusive.</i>" \
>> % (shortNum, str(typeNum), colName, theVal, str(typeNum))
>>
>> colName == 'LastDatePrice'
>> typeNum = 10
>>
>> elif 10 < int(typeNum) < 20:
>> shortNum = '10'
>>
>> Therefore...
>> shortNum = '10'
>>
>> if whatDo == 'insert':
>> theVal = defaultVal
>> val = defaultVal
>>
>> Since whatDo == 'insert'...
>> and
>> val = 'yyyy/mm/dd'
>> therefore
>> theVal = None
>>
>> Now, this value of None doesn't cause any problems with the other values
>> printed out. This is the code:
>>
>> print 'printTheForm: ', descrProds, '<br />'
>> for value in descrProds:
>> print 'value: ', value, '<br />'
>>
>> that produces this print-out:
>>
>> printTheForm: [['ID', 'tinyint', '5', '0', None], ['SKU', 'varchar', '40',
>> '', None], ['Category', 'varchar', '40', '', None], ['Name', 'varchar',
>> '50', '', None], ['Title', 'varchar', '100', '', None], ['Description',
>> 'mediumtext', '100', '', None], ['Price', 'float', '8', '0.0', None],
>> ['SortFactor', 'int', '4', '0', None], ['Availability', 'tinyint', '1', '0',
>> '1'], ['OutOfStock', 'tinyint', '1', '0', '0'], ['ShipFlatFee', 'float',
>> '5', '0.0', '0.00'], ['ShipPercentPrice', 'tinyint', '2', '0', '0'],
>> ['ShipPercentWeight', 'tinyint', '2', '0', '0'], ['Associations', 'varchar',
>> '40', '', None], ['TempPrice', 'tinyint', '1', '0', None], ['LastDatePrice',
>> 'date', '10', 'yyyy/mm/dd', None], ['Weight', 'float', '7', '0.0', None],
>> ['Metal', 'enum', ['14k gold', '18k gold', 'white gold', 'silver',
>> 'tungsten', 'titanium'], '', None], ['PercentMetal', 'tinyint', '2', '0',
>> None], ['colorsShadesNumbersShort', 'set', [''], '', None]]
>> value: ['ID', 'tinyint', '5', '0', None]
>> value: ['SKU', 'varchar', '40', '', None]
>> value: ['Category', 'varchar', '40', '', None]
>> value: ['Name', 'varchar', '50', '', None]
>> value: ['Title', 'varchar', '100', '', None]
>> value: ['Description', 'mediumtext', '100', '', None]
>> value: ['Price', 'float', '8', '0.0', None]
>> value: ['SortFactor', 'int', '4', '0', None]
>> value: ['Availability', 'tinyint', '1', '0', '1']
>> value: ['OutOfStock', 'tinyint', '1', '0', '0']
>> value: ['ShipFlatFee', 'float', '5', '0.0', '0.00']
>> value: ['ShipPercentPrice', 'tinyint', '2', '0', '0']
>> value: ['ShipPercentWeight', 'tinyint', '2', '0', '0']
>> value: ['Associations', 'varchar', '40', '', None]
>> value: ['TempPrice', 'tinyint', '1', '0', None]
>> value: ['LastDatePrice', 'date', '10', 'yyyy/mm/dd', None]
>>
>> If in fact the problem has to do with the None value, how can I easily
>> substitute a different value? I tried:
>>
>> if theVal == None:
>> theVal = ''

Taken from: http://boodebr.org/main/python/tourist/none-empty-nothing:

tags = parse_file(filename)
if tags is None:
print "** ERROR **"
elif len(tags) == 0:
print "Empty file"
else:
print "OK!"

>>
>> but that didn't capture it.
>>
>
> Update:
> It's a date value (not datetime). I updated the database to default to the
> value "2000-01-01" but that didn't help (gave the same print-out as above).
>
>
>> TIA,
>> beno
>>
>

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Re: [gtk-win32] cannot import glib in python shell

2009-12-23T12:07:45Z

> , but when I do
> import glib
> ERROR!!!

My Python knowledge is next to nil. You might get more help on some
Python-specific list. Or even a pygtk-specific list.

> if I cd to a certain dir in glib sources, there were two .py files,

Wrong approach. And anyway, I find four .py files in current GLib
sources. They are completely unrelated to the GLib Python binding
which is what you want. The GLib Python binding is not in the GLib
sources.

> but I didn't know where to place them in the python26 dir.

Good, because you shouldn't. Look in the Makefile.am to get an idea
what these files are used for. Or just read them. As I said, they are
not what you apparently think they are.

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Re: More On the Strange Problem

2009-12-23T12:04:02Z

On Wed, Dec 23, 2009 at 3:03 PM, MRAB <python@...> wrote:

Victor Subervi wrote:

I've isolated the problem in the print-out at the bottom of this post. It occurs when these values are passed:

['LastDatePrice', 'date', '10', 'yyyy/mm/dd', None],

Since this is the first datetime that is passed, it would appear to be associated with such values, which are processed thus:

elif typeName == 'datetime':

Where does the value of typeName come from?

It is the descriptor of the MySQL type.

print "<input type='text' width='%s' maxlength='%s' name='%s' value='%s' /> " \
"<i>This field takes a datetime up to %s alphanumeric characters inclusive.</i>" \
% (shortNum, str(typeNum), colName, theVal, str(typeNum))

colName == 'LastDatePrice'
typeNum = 10

elif 10 < int(typeNum) < 20:

If typeNum is 10 then 10 < int(typeNum) < 20 is False.

Thank you for catching that! However, the code is followed by an else clause.

shortNum = '10'

Therefore...
shortNum = '10'

if whatDo == 'insert':
theVal = defaultVal
val = defaultVal

What's the difference between theVal and val? The names don't help me!
:-)

    if whatDo == 'insert':
      theVal = defaultVal
      val = defaultVal
    else:
      theVal = val

Since whatDo == 'insert'...
and
val = 'yyyy/mm/dd'
therefore
theVal = None

Now, this value of None doesn't cause any problems with the other values printed out. This is the code:

print 'printTheForm: ', descrProds, '<br />'
for value in descrProds:
print 'value: ', value, '<br />'

that produces this print-out:

printTheForm: [['ID', 'tinyint', '5', '0', None], ['SKU', 'varchar', '40', '', None], ['Category', 'varchar', '40', '', None], ['Name', 'varchar', '50', '', None], ['Title', 'varchar', '100', '', None], ['Description', 'mediumtext', '100', '', None], ['Price', 'float', '8', '0.0', None], ['SortFactor', 'int', '4', '0', None], ['Availability', 'tinyint', '1', '0', '1'], ['OutOfStock', 'tinyint', '1', '0', '0'], ['ShipFlatFee', 'float', '5', '0.0', '0.00'], ['ShipPercentPrice', 'tinyint', '2', '0', '0'], ['ShipPercentWeight', 'tinyint', '2', '0', '0'], ['Associations', 'varchar', '40', '', None], ['TempPrice', 'tinyint', '1', '0', None], ['LastDatePrice', 'date', '10', 'yyyy/mm/dd', None], ['Weight', 'float', '7', '0.0', None], ['Metal', 'enum', ['14k gold', '18k gold', 'white gold', 'silver', 'tungsten', 'titanium'], '', None], ['PercentMetal', 'tinyint', '2', '0', None], ['colorsShadesNumbersShort', 'set', [''], '', None]]
value: ['ID', 'tinyint', '5', '0', None]
value: ['SKU', 'varchar', '40', '', None]
value: ['Category', 'varchar', '40', '', None]
value: ['Name', 'varchar', '50', '', None]
value: ['Title', 'varchar', '100', '', None]
value: ['Description', 'mediumtext', '100', '', None]
value: ['Price', 'float', '8', '0.0', None]
value: ['SortFactor', 'int', '4', '0', None]
value: ['Availability', 'tinyint', '1', '0', '1']
value: ['OutOfStock', 'tinyint', '1', '0', '0']
value: ['ShipFlatFee', 'float', '5', '0.0', '0.00']
value: ['ShipPercentPrice', 'tinyint', '2', '0', '0']
value: ['ShipPercentWeight', 'tinyint', '2', '0', '0']
value: ['Associations', 'varchar', '40', '', None]
value: ['TempPrice', 'tinyint', '1', '0', None]
value: ['LastDatePrice', 'date', '10', 'yyyy/mm/dd', None]

If in fact the problem has to do with the None value, how can I easily substitute a different value? I tried:

if theVal == None:

The Pythonic way is to use "is" when comparing with singletons like

None.

Can you please explain by example?

theVal = ''

but that didn't capture it.

What do you mean by "didn't capture it"?

The output was identical to what I originally posted.
TIA,
beno

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