🌐 Mailman 3 September 2006 - Python-list - python.org

fun with unicode files
by Thomas Heller May 19, 2007

May 19, 2007

I want to use ConfigParser with both NT4-style .reg files, which are ascii (or ansi?) files, and XP-stype .reg files which seem to be UTF-16 encoded unicode-files (hope that's the correct terminology). [And yes, I have read the warning in the manual that ConfigParser doesn't interpret the value-type prefixes in the reg files] Here's the start of the method I wrote to detect the encoding and read the file: def _parse_regfile(self, filename): ifi = open(filename, "r") import codecs, StringIO if ifi.read(2) in (codecs.BOM_LE, codecs.BOM_BE): ifi.close() ifi = codecs.open(filename, "r", "utf-16") I wonder: do I really have to check for the BOM manually, or is there a Python function which does that? Continuing the code: # ConfigParser calls .readline(), but: # NotImplementedError: '.readline() is not implemented for UTF-16' # so we need to put the data into a StringIO instance. # Um, cStringIO doesn't handle unicode correctly, so we'll have # to use the slower StringIO ifi = StringIO.StringIO(ifi.read()) ifi.readline() # skip the first two lines ifi.readline() c = ConfigParser() c.readfp(ifi) return c Is there a better way to do this? Why doesn't the UTF-16 codec implement readline()? Thomas

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Uninstall speed with Python 2.4 MSI
by David Bolen May 19, 2007

May 19, 2007

Although it isn't often necessary, I tend to be in the habit of uninstalling Python before updating to new minor releases, or especially during the alpha/beta cycle. I'm in the process of uninstalling 2.4a2 to install 2.4a3 and the uninstall is running absolutely dog slow and burning 100% cpu while doing it (all going to mshta.exe). Watching the progress bar it almost seems to be doing a whole bunch of operations per file or something. The mshta process went away after the removal so I don't believe there was any other scripting running on my system simultaneously. It probably took 5+ minutes for the removal. I can't recall if removing 2.4a1 was like this, but certainly the non-MSI versions weren't, even when all the docs were separate files. I was wondering if anyone else has experience this? I may not have the fastest system at the moment, but this has to have been one of the slowest (proceeeding, if not absolute time) uninstalls I've done in a long while. -- David

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Re: LRU cache (and other things missing from the standard library ...)
by Evan Prodromou March 30, 2007

March 30, 2007

Gerhard, I agree that LRU caches are a data structure too frequently re-implemented in Python. I'd also like to see a "standard" cache package, either as part of the standard library or elsewhere. To that end, I've just uploaded an LRU cache package to the Python Package Index: http://www.python.org/pypi?:action=display&name=lrucache&version=0.2 Please, let me know if there are features you'd need from a cache class that aren't present, implementation improvements that could be made, or what have you. I'm working on a version 0.3 that includes a transparent cache wrapper and LRU memoization for functions. ~ESP -- Evan Prodromou .O. http://bad.dynu.ca/~evan/ ..O evan(a)bad.dynu.ca OOO

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Mark Lutz Python interview
by Mark Lutz Dec. 13, 2006

Dec. 13, 2006

Python author and trainer Mark Lutz will be interviewed on the radio show Tech Talk this Sunday, October 1st, at 6PM Eastern time. He'll be answering questions about Python, his books, and his Python training services. For more details about the show, see Tech Talk's website at http://techtalk.imi-us.com. You can also listen to the live webcast of the show on KFNX's website, http://www.1100kfnx.com. --Python Training Services http://home.earthlink.net/~python-training

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where the extra space comes from on the stdout
by alf Dec. 9, 2006

Dec. 9, 2006

Hi, I can not find out where the extra space comes from. Run following: import os,sys while 1: print 'Question [Y/[N]]?', if sys.stdin.readline().strip() in ('Y','y'): #do something pass $ python q.py Question [Y/[N]]?y Question [Y/[N]]?y Question [Y/[N]]?y Question [Y/[N]]?y Question [Y/[N]]?n Question [Y/[N]]? Question [Y/[N]]? There is a space evrywhere just before Q Any insight? -- alfz1

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testing for valid reference: obj vs. None!=obs vs. obj is not None
by alf Dec. 9, 2006

Dec. 9, 2006

Hi, I have a reference to certain objects. What is the most pythonic way to test for valid reference: if obj: if None!=obs: if obj is not None: -- alfz1

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Re: urllib en https
by jjl＠pobox.com Nov. 10, 2006

Nov. 10, 2006

Dennis Lee Bieber <wlfraed(a)ix.netcom.com> writes: > On Wed, 13 Sep 2006 23:03:08 +0200, Cecil Westerhof <dummy(a)dummy.nl> > declaimed the following in comp.lang.python: > > > > > I found the problem. The first Python was compiled with ssl support enabled > > and the second without ssl support enabled. > > A vision is forming in the crystal ball... I see... ActiveState... > > As I recall, ActiveState doesn't distribute the SSL package that the > python.org package contains. But... It is possible to copy the SSL > related files from a python.org package into the ActiveState > installation. Does ActiveState do a unix distribution of Python now? (The OP seemed to have a Unix-like system -- so probably he didn't install have the right rpm or whatever installed -- a very common problem with people trying to use SSL on linux distributions.) John

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Classes referencing each other
by Manuel Bleichner Nov. 6, 2006

Nov. 6, 2006

Hello list, I have searched for some time now, but no result... I'm having the following problem: In a module I have a huge number of classes of the form: class A(object): connected_to = [B, C] <other attributes...> class B(object) connected_to = [C] <other attributes...> class C(object) connected_to = [A] <other attributes...> As you see, classes A and B reference classes that are not yet defined when the class is being defined. It will raise a NameError: 'B'. I know i could solve this by leaving out the definition of 'connected_to' in A and attach it to the class later on by A.connected_to = [B, C] but I would like to avoid this, because in the module there are about 50 classes that have to be altered from time to time and it's just incredibly ugly if I have to look for the attribute definitions in more than one place. Also, I would like to avoid eval(), because the references have to be followed very often and that would cause more CPU load and make the program code uglier :) If anyone of you knows a neat way to solve this, I'd be very grateful. Greetings, Manuel

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Embedding Matplotlib images into wxPython
by dr_tyson＠hotmail.com Oct. 27, 2006

Oct. 27, 2006

I am trying to embed images into a wxPython app (created using Boa Constructor), but have not been able to do so. I know how to embed plots, but images seem to be a problem. I've tried using code analogous to the example given at the Matplotlib website to no avail. If anybody has been successful at this could you please post some sample code? That would be greatly appreciated. Thanks! Randy

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Re: Problems with Python 2.5 installer.
by John Machin Oct. 13, 2006

Oct. 13, 2006

Matthew Warren wrote: > -----Original Message----- > From: python-list-bounces+matthew.warren=digica.com(a)python.org > [mailto:python-list-bounces+matthew.warren=digica.com@python.org] On > Behalf Of paw > Sent: 29 September 2006 11:01 > To: python-list(a)python.org > Subject: Re: Problems with Python 2.5 installer. > > > John Machin wrote: > > paw wrote: > > > I have ran the MSI installer for Python 2.5 several times attempting > to > > > install to C: > > > Python, however all of the files are placed in C:\ . The installer > is > > > told to only install files for me, beyond that I have only chosen > the > > > defaults. > > > > What do you mean by "install to C: <newline> Python"? Can you tell us > > (unambiguously, on one line) what directory you chose? Is there any > > good reason why you didn't take the default, which is > > C:\Python25 > > ? > > > Could this happen if c:\python does not exists and creating it fails for > some reason, or if permissions are incorrect? Are you installing it as a "normal" user or as an Administrator? I have occasionally had problems (not when installing Python) as a "normal" user not being allowed to create a folder at the C:\ level. I'd suggest this; (1) log on as as administrator (i.e. with full rights) (2) do an "all users" installation (3) You haven't come up with a good reason for doing otherwise, so read my lips: *** use the default installation folder C:\Python25 *** you'll be happy you did, when Python 2.6 comes out and you want to have both installed. HTH, John

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