🌐 Mailman 3 December 2004 - Python-list - python.org

Re: Probleme mit der Installation der openSource Bittorrent.... python vs JAVA
by JanC Dec. 31, 2004

Dec. 31, 2004

Gerhard Haering schreef: > I can understand your emotions here. OTOH it's typical for Germans > (and even more so French) to assume that everybody speaks their > language. The same is true for English language speakers in my experience... (E.g.: why is this international newsgroup in English only?) > [*] The very minimum of netiquette would require to read a few > messages in the newsgroup/mailing list and check what it is about and > in what language it is. Hm, be.* newsgroups are officially "quadrilingual" (Dutch, French, German & English), but in practice 99,99% of the messages are in Dutch, so reading a few messages won't help much... ;-) -- JanC "Be strict when sending and tolerant when receiving." RFC 1958 - Architectural Principles of the Internet - section 3.9

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what would you like to see in a 2nd edition Nutshell?
by aleaxit＠yahoo.com Dec. 31, 2004

Dec. 31, 2004

I'm considering proposing to O'Reilly a 2nd edition of "Python in a Nutshell", that I'd write in 2005, essentially to cover Python 2.3 and 2.4 (the current 1st edition only covers Python up to 2.2). What I have in mind is not as complete a rewrite as for the 2nd vs 1st edition of the Cookbook -- Python hasn't changed drastically between 2.2 and 2.4, just incrementally. Language and built-ins additions I'd of course cover -- decorators, custom descriptors (already in 2.2 but not well covered in the 1st edition), importing from zipfiles, extended slicing of built-in sequences, sets, genexps, ... and also major new standard library modules such as (in no special order) optparse, tarfile, bsddb's new stuff, logging, Decimal, cookielib, datetime, email... and new capabilities of existing modules, such as thread-local storage. Outside of the standard library, I was thinking of expanding the coverage of Twisted and adding just a few things (numarray -- perhaps premature to have it _instead_ of Numeric, though; dateutils, paramiko, py2app...). Since the book's size can't change much, I'll also have to snip some stuff (the pre-email ways to deal with mail, for example; modules asyncore and asynchat, probably) to make space for all of the additions. I haven't take any real decisions about it, yet, except one: I'll keep covering Tkinter, rather than moving to, say, wxPython (no space to _add_ wx coverage while leaving Tk intact - having to choose, I still believe Tkinter coverage is going to help more readers). Just about everything else is still to be finalized in my mind... So, if there's any advice or request about a 2nd edition of the Nutshell, this is the right time for y'all to let me know. Feedback is welcome, either privately or right here. Thanks in advance -- _and_ apologies in advance because I know I just won't be able to accomodate all the requests/advice, given the constraints on book size &c. Alex

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RE: The Industry choice
by Walter S. Leipold Dec. 31, 2004

Dec. 31, 2004

Paul Rubin writes: > I don't know that C# is really that much different from Python. > I haven't used it but I have the impression that it's sort of similar > under the skin. Nope nope nope. C# is a statically typed, statically compiled (i.e., no eval(...) or exec(...)), single-inheritance langauge with a bondage-and-discipline syntax almost identical to Java's. It compiles to run on the Common Language Runtime, which is conceptually similar to the JVM. Other than some syntactic sugar, C#'s primary difference from the latest Java (v1.5) is that its standard libraries (the .Net stuff) are much poorer -- this is particularly noticeable in its Collections API. -- Walt

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OT: novice regular expression question
by It's me Dec. 31, 2004

Dec. 31, 2004

I am never very good with regular expressions. My head always hurts whenever I need to use it. I need to read a data file and parse each data record. Each item on the data record begins with either a string, or a list of strings. I searched around and didn't see any existing Python packages that does that. scanf.py, for instance, can do standard items but doesn't know about list. So, I figure I might have to write a lex engine for it and of course I have to deal wit RE again. But I run into problem right from the start. To recognize a list, I need a RE for the string: 1) begin with [" (left bracket followed by a double quote with zero or more spaces in between) 2) followed by any characters until ] but only if that left bracket is not preceeded by the escape character \. So, I tried: ^\[[" "]*"[a-z,A-Z\,, ]*(\\\])*[a-z,A-Z\,, \"]*] and tested with: ["This line\] works"] but it fails with: ["This line fails"] I would have thought that: (\\\])* should work because it's zero or more incidence of the pattern \] Any help is greatly appreciated. Sorry for beign OT. I posted this question at the lex group and didn't get any response. I figure may be somebody would know around here.

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Re: Why are tuples immutable?
by Antoon Pardon Dec. 31, 2004

Dec. 31, 2004

Op 2004-12-21, Nick Coghlan schreef <ncoghlan(a)iinet.net.au>: > Antoon Pardon wrote: >> Why then doesn't python think the same about sorted lists. When I have a >> sorted list and do operations on it that depend on it being sorted, >> I can mess things up just as easily by mutating an element in that >> sorted list as I can mess things up by mutating a dictionary key. > > Incorrect, and this appears to be the point where our major disagreement lies. > > Mutate a value in a sorted list and you can fix that easily, just by calling its > sort() method again (and, in fact, mutate and resort is a fairly common idiom > for small datasets). 'sorted' and 'heapified' are list properties that are > easily broken by direct manipulation, but are also easily restored by once again > 'sorting' or 'heapifying'. That is an implemantation detail. Likewise a dictionary is probably not always in a sane state when a new key is inserted. The fact remains that in a sorted list or a heap, mutating an element arbitrarily can mess up things greatly. > Change the hash value of an item used as a key in a dictionary, and *the > internal state of the dictionary is likely to broken in a manner you probably > cannot fix*. The only reason the 'probably' is there is because you should be > able to 'fix it' by changing the hash value back to what it was originally. I could argue that this is then a failing of dictionary that doesn't provide a method to clean up after a key is mutated. > Waitasec - wouldn't it be easier if dictionaries just made it a rule that the > hash value wasn't allowed to change? Hang on, that's exactly what they do. No it is not. And yes I know what to do if I want to use mutable keys as objects. I'm just argueing against those who think that should be somehow forbidden. -- Antoon Pardon

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ANN: matplotlib-0.70
by John Hunter Dec. 31, 2004

Dec. 31, 2004

matplotlib is a 2D graphics package that produces plots from python scripts, the python shell, or embeds them in your favorite python GUI -- wx, gtk, tk, fltk currently supported with qt in the works. Unlike many python plotting alternatives is written in python, so it is easy to extend. matplotlib is used in the finance industry, web application servers, and many scientific and enginneering disciplines. With a large community of users and developers, matplotlib is approaching the goal of having a full featured, high quality, 2D plotting library for python. A lot of development has gone into matplotlib since the last major release, which I'll summarize here. For details, see the notes for the incremental releases at http://matplotlib.sf.net/whats_new.html. Major changes since matplotlib-0.60 - The alpha version of the users guide - http://matplotlib.sf.net/users_guide.pdf. There are still a number of sections to be completed, but it's a start! - The matlab namespace renamed pylab - if you are upgrading from a version older than 0.64, please remove site-packages/matplotlib before upgrading. See http://matplotlib.sourceforge.net/matlab_to_pylab.py - New plot types: contour plots (contour), polar charts (polar), horizontal bar charts (barh), pie charts (pie), sparse matrix visualization (spy and spy2). Eg, http://matplotlib.sf.net/screenshots.html#polar_demo - Full ipython http://ipython.scipy.org integration in the "pylab" mode for interactive control of matplotlib plots from the python shell. - A significantly improved interactive toolbar for panning, zooming, zoom to rect - see http://matplotlib.sf.net/tutorial.html#toolbar2. - New backends: FLTK, Cairo, GTKCairo - Text - rotated mathtext, mathtext for postscript, text bounding boxes - Colormaps - 14 colormaps built-in http://matplotlib.sf.net/screenshots.html#pcolor_demo - Images - performance optimizations for 4x faster large image handling, PIL support, interpolation and colorbar improvements, imread - Event handling for capturing mouse clicks, movements, keypresses, etc. - same pylab interface works across GUIs. See examples/keypress_demo.py, examples/picker_demo.py, examples/coords_demo.py - set and get matlab style property introspection - http://matplotlib.sf.net/examples/set_and_get.py - improved dates handling for dates and date string formatting from 0000-9999, eg http://matplotlib.sf.net/screenshots.html#finance_work - Be sure to check out the 120 examples at http://matplotlib.sf.net/examples Home page : http://matplotlib.sourceforge.net Downloads : http://sourceforge.net/projects/matplotlib Screenshots : http://matplotlib.sourceforge.net/screenshots.html Tutorial : http://matplotlib.sourceforge.net/tutorial.html Credits : http://matplotlib.sourceforge.net/credits.html John Hunter

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Re: Urgently need Elecronic version of book:Python Network programming by John Goerz
by Steve Holden Dec. 31, 2004

Dec. 31, 2004

mch2k2 wrote: > Hello All > > I have just started working on Pyhton. > I need urgent help regarding Python Network Programming. > I want the elctronic version of the Book: Foundations of Python > Network programming by John Goerzen. > If anybody among you have that please forward at my mailID. > Thank you in advance. > ... otherwise, because my need is so urgent that I probably won;t be monitoring the newsgroup, please bring a paper copy to my home between the hours of 8:30 and 9:30 am. Sorry, probably not as funny as I though, but honestly, "Python Network Programming" is a *book*. Who even knows whether there *is* an electronic version (APress would be a good site to visit, since they are the publishers). Why not, instead, explain what your *real* problem is? There's a good chance that there may already be some Python on the 'Net that addresses the issue, and saves you from building it from scratch. But if you don;t tell us what you need to do, we'll never know. Or perhaps you just want to publish an unauthorized Indian edition of "Python Network Programming". How can we tell? regards Steve -- Steve Holden http://www.holdenweb.com/ Python Web Programming http://pydish.holdenweb.com/ Holden Web LLC +1 703 861 4237 +1 800 494 3119

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HELP: Strange behaviour of subprocess
by Pekka Niiranen Dec. 31, 2004

Dec. 31, 2004

Hi there I have installed Cygwin to my w2k machine and use Python to execute Bash -shell scripts. I noticed that in script below parameter "shell=False" causes raw_input() to fail; the only way to stop script is to kill the Dos window where it is run (The Bash shell runs OK listing directory contents to screen). Any comments anybody? ---script starts-- import os, subprocess, sys try: retcode = subprocess.call("c:\\cygwin\\bin\\bash.exe -c\ /usr/bin/ls", shell=False) 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 raw_input("press any key") ---script ends--

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Python + Lisp integration?
by Simo Melenius Dec. 31, 2004

Dec. 31, 2004

Hi, I'm wondering (after a bit of googling) whether there exists a Python binding to any open source Lisp environment (like librep or some Scheme or Common Lisp implementation) that could be recommended for non-toy use? My intention would be to use the Lisp environment to augment and help my Python programming (and/or conversely: have access to the wealth of Python libraries and Python code from a lispy language), which yields at least the following requirements: - the type and runtime environment system would need to be quite transparently integrated, e.g. being able to use (pass, call, set/get attr) Python objects in Lisp and vice versa with minimum hassle - the performance should match at least that of Python's. That probably requires a native interpreter, although the ability to compile Lisp to Python bytecode could do (if the lispy language could be efficiently implemented in the Python bytecode) There are many Scheme/Lisp interpreters written in Python, but those I've found and looked at I consider to be more of proof of concepts. Nesting different interpreters costs probably an order of magnitude in speed.

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lies about OOP
by projecktzero Dec. 31, 2004

Dec. 31, 2004

I know this might not be the correct group to post this, but I thought I'd start here. A co-worker considers himself "old school" in that he hasn't seen the light of OOP.(It might be because he's in love with Perl...but that's another story.) He thinks that OOP has more overhead and is slower than programs written the procedural way. I poked around google, but I don't know the magic words to put in to prove or disprove his assertion. Can anyone point me toward some resources? We do web programming. I suspect that OO apps would behave as good as procedural apps, and you'd get the benefit of code reuse if you do it properly. Code reuse now consists of cutting and pasting followed by enough modification that I wonder if it was worth it to cut and paste in the first place. Thanks.

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