🌐 Mailman 3 December 2000 - Python-list - python.org

Announce: Mississippi Python Interest Group
by R. A. Jan. 15, 2001

Jan. 15, 2001

MS PIGgie (MS Python Interest Group) is a new group for people interested in Python. The new website and email list are intended to develop into useful resources, and membership is loosely defined. Mississippi Needs Elegant Code Rob Andrews -- Mississippi Python Interest Group http://www.lowerstandard.com/python/mspiggie

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What's the difference?
by simon＠uggs.demon.co.uk Jan. 15, 2001

Jan. 15, 2001

Whats the difference between : #! /usr/bin/env python and : #! /usr/bin/python ?? -- Simon Foster Cheltenham England

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Re: One Python 2.1 idea
by rturpin＠my-deja.com Jan. 12, 2001

Jan. 12, 2001

Tim Peters raises some very good points. I am thinking on them, as much as my post-Christmas, brandied brain allows. For now, two things. First, I hope Alex Martelli does look at how list comprehension is implemented. Even though I am the one who has argued that the language features of Python are quite mature, I think list comprehension is just the right kind of language enhancement, raising the level of abstraction in a way that extends seamlessly the existing notation. Second, a question. Consider the invocation of a method, such as: x.foo() Does this really cause the lookup of the string "foo" in x's namespace dictionary? The first time? Every time? Is this also the case when data members are accessed? Hoping-everyone-had-a-good-holiday'ly yrs, Russell Sent via Deja.com http://www.deja.com/

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Re: P*rl in Latin, whither Python?
by Erik Max Francis Jan. 12, 2001

Jan. 12, 2001

Steve Lamb wrote: > >I take it Italian is too close to Latin for you? :) How about > > Japanese? I > >heard (though cannot verify) that Japanese was pretty orthogonal, and > > should > >be easily computer parsable (compared to, say, English or German. ;) > > ). > > Esperanto. :) Vi estas tre amuza. -- Erik Max Francis / max(a)alcyone.com / http://www.alcyone.com/max/ __ San Jose, CA, US / 37 20 N 121 53 W / ICQ16063900 / &tSftDotIotE / \ All the people in her neighborhood turn around and get mad and sing \__/ Public Enemy Official Buh rules / http://www.alcyone.com/max/projects/cards/buh/ The official rules to the betting card game, Buh.

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Re: Season's greetings (was Re: Some Python 2.1 ideas)
by Alex Martelli Jan. 9, 2001

Jan. 9, 2001

"Tim Peters" <tim.one(a)home.com> wrote in message news:mailman.977765348.13376.python-list@python.org... > [Bob Alexander] > > P.S. Merry Christmas! > > [Aahz Maruch] > > Bah, humbug. > > Sounds like you need something to cheer you up, Santa Aahz! Elf Timmy has Me, I had the best Christmas ever since I got my first electric train... got to show Python to my son (Pascal and Assembler his only previous programming experiences), and again and again he got the jaw-drops-"but-it-CAN'T-be-THAT-powerful!" effect which I well recall from my early Python days. (And as a cherry on top he kibitzed me for an OKbridge session where I got close to 70%, but the Python part alone would have, by itself, been quite enough...!-). One thing I wasn't able to easily answer -- what's the *easiest* way for a Python beginner to do function-plots, with nicely labeled graphs, minor/major ticks, color, auto-scaled, &c &c? On-screen display the major need, though nice printouts wouldn't hurt either. Speed no issue, as his new PC is twice as fast as mine!-) I tried downloading DISLIN but it appears to embed its own Python, need its own setting of PYTHONPATH; and (from a superficial look at it) it doesn't seem to do auto scaling. Any suggestions? I'd like to keep amazing him with Python power and ease, as what dad wouldn't like for his late-teenage son...:-). Alex

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CGI with Python
by u＠book.co.th Jan. 9, 2001

Jan. 9, 2001

Hi experts, I am very new with python and linux. and i want to create a CGI script in binary format. first of all, i had a script that written in .py. and i compiled it with python command line... python -c "import sourcefile" after that i got a file with .pyc extension in a binary format. is it able to run as CGI? anyway i heard that there is a tool called "Freeze". i have tried to freeze a .py code to make an executable file... you know?, it made a huge executable... any suggestion? regards, Sent via Deja.com http://www.deja.com/ Before you buy.

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Problems with the re module on IRIX
by Yogi Parish Jan. 8, 2001

Jan. 8, 2001

Hello, everybody I cannot get the re module to run on an SGI. (1.5.2) Has anybody had similar experiences with such a problem (make test fails in test_re).... what can I do? thanx yogi

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2001 Enchancement Wishlist
by Raymond Hettinger Jan. 6, 2001

Jan. 6, 2001

If these ideas meet with favor, I'll write-up a PEP. 1. List.append(elem) and List.pop() are great. Let's add two more methods, List.prepend(elem) and List.leftpop(). The goal is to make queues,deques, and reverse stacks easier, faster, and clearer to implement. 2. There is already a PEP to extend the eval() function which is currently limited to dictionaries. The goal is to accept any object defining __getitem__() so that any mapping object can be used to specify the globals and locals. I recommend that we extend the same courtesy to the % string formatting operator. For example: print "Spam with %s, eggs, and spam" % aUserDictionary 3. __init__ is the only special method that doesn't allow a return value. I think it should continue to return the new object by default but also allow another return item to be substituted. For example: def __init__( self ): if MyClass.aSingleton == None: MyClass.aSingleton = self return MyClass.aSingleton 4. Allow dictionaries to respond to sequence operations as if .keys() were in the list object. Examples: knights = { 'lancalot':'good', 'gallahad':'brave', 'robin':'coward' } for name in knights: print name, knights[name] print knights.len() if 'arthur' in knights: print 'Not the King' print knights[0] # may be any one depending on the hash table order try: print knights[5] except IndexError: print 'Too few knights for the ladies in the castle' del knights['lancelot'] # regular mapping operations left unchanged. I believe all of the enhancements can be added without impacting existing programs. Hope suggestion #4 isn't too radical. Happy New Year, Raymond Hettinger othelloNOSPAM(a)javanet.com

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~Python ?
by gerson.kurz＠t-online.de Jan. 5, 2001

Jan. 5, 2001

On Linux, ~ usually refers to the users homedir, but not so in Python (at least, in ActivePython 2.0). I found out the hard way when using a script that issued os.makedirs() relative to ~ - It created an actual directory named ~. You can have real fun if you try to deleting an actual directory named ~ on Linux, boy. I understand that ~ is probably handled by the shell, but if Python doesn't deal with it, its hard to use Python in some kinds of scripts. (I think Perl, Pythons ugly twin-brother, does)

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Re: Good introduction to functional programming with Python?
by Alex Martelli Jan. 5, 2001

Jan. 5, 2001

"Tim Peters" <tim.one(a)home.com> wrote in message news:mailman.977465166.28872.python-list@python.org... > [Richard P. Muller] > > Can someone recommend a decent introduction to functional programming > > in Python? > > I doubt it, but if you want to learn FP I strongly recommend checking out > the freely available Haskell material: > > http://www.haskell.org/ http://sourceforge.net/projects/xoltar-toolkit/ has Python utilities for better support for some Haskell-like functional programming in Python, including the key Haskell semantic idea, lazy evaluation. Haskell is my favourite FP language, and it does have some nice surface similarities with Python (use of whitespace, the list comprehension idea), but it differs deeply from Python in two key issues (which are NOT really central to FP...): a. lazy evaluation is always the default semantics b. very strict (and elegant) static typing Python evaluates eagerly by default (like almost all languages!), and its typing is always dynamic. If one wants to broaden one's mind, looking at the world from a very different angle than Python's, then Haskell makes a LOT of sense. A 'triangulation' is best done by choosing two 'base points' that are not TOO close to each other, and nobody would accuse Haskell and Python of being too close, given [a] & [b]. Incidentally, while haskell.org is a great site, I would strongly suggest that books are by far the best way to learn Haskell. Hudak's "Haskell School of Expression" (Cambridge University Press) may well wow you if you're into multimedia & such; Thompson's more traditional "Craft of Functional Programming" 2nd ed (Addison Wesley) is workmanlike, thorough, and clear. From there you can move on to Fethi's and Lapalme's "Algorithms: a Functional Programming Approach" (Addison-Wesley) and Okasaki's "Purely Functional Data Structures", and finally HAVE a good grasp of FP the Haskell way (Okasaki's work actually focuses on ML, with Haskell equivalents in an appendix, so you'll be getting a small apercu of non-lazy FP thrown in for free:-). On the other hand, if one's focus is on understanding how best to apply FP *in a Python setting*, this FP curriculum may prove too round-about -- the conceptual detours through static typing and "laziness as a way of life", in particular, are surely scenic and mind-broadening, but not specifically relevant. There are faster and more direct ways... > > I haven't found any suitable intro, and I'd like to learn more > > about map(), apply(), lambda, and the like. > > Haskell will teach you that. You can come back and apply what you learned > in Python then -- although some people will cluck at you <wink>. > > > I understand the syntax, but I'd like to learn something of > > the functional programming context these commands come from. > > If you want to learn French, don't go to Manchester. Functional programming > features are not central to Python -- its support for them is spotty, clumsy > and unlikely to get fancier. Learn FP in a context where it's natural! And > Haskell is the most Pythonic of all languages that have nothing in common > with Python. There must indeed be some Pythonic 'aura' to Haskell, I guess, given the somewhat surprising correlation between liking Haskell and liking Python among people who've tried both. But points [a] and [b] above are BIG technical differences, and not centrally relevant to FP. There ARE functional programming languages with dynamic typing AND eager (strict) evaluation models like Python. A 'pure' FP with these characters is up-and-coming Erlang -- but I would not necessarily suggest it here, because its central semantic concern is with issues of parallelism and concurrency, which have relatively little to do with the issue. A NON-pure language one SHOULD consider for its didactical strength is Scheme. Abelson's and Sussman's "Structure and Interpretation of Computer Programs" will teach one Scheme in a strongly FP-oriented setting, and it's a great book on its own -- I consider SICP as one of the main conceptual motivation to learn a little Scheme, just as Kernighan and Pike's "The Practice of Programming" is motivation enough to learn some C, or Fowler's "Refactoring" motivates one to pick up 'just enough Java to get by'. Scheme's syntax will feel pretty alien, what with all the darned parentheses, but, with Abelson and Sussman at hand, one soon gets past that and focuses on really deep and fascinating concerns. http://www.cs.rice.edu/CS/PLT/packages/drscheme/ gives a free and very good implementation, with all the trimmings and a lot of equally-free didactical support, good for any Win32 box, Mac, or Unixoid. (Not that Haskell's and Erlang's implementations are any less free, cross-platform, and good-quality, but, IMHO, Rice's Scheme has characteristics that make it even better). Alex

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