🌐 Mailman 3 September 2010 - Python-list - python.org

Request For Comments: Learn Python The Hard Way
by Zed Shaw Sept. 29, 2010

Sept. 29, 2010

Hi Everyone, I rarely post to the list, but I'm getting near the end of the book I wrote to help people learn Python and I would like some feedback on it if you please: * Web: http://learnpythonthehardway.org/ * PDF: http://learnpythonthehardway.org/static/LearnPythonTheHardWay.pdf The book so far has been successful in teaching Python to people who couldn't learn it previously, but I have to still test it with real learners more extensively. It is also in rough draft form, so any grammar errors, spelling, or just plain wrong code/concepts/terms are possible. I'd appreciate if Python experts and newbies could read through the book or choice sections and submit tickets to me if you find errors: http://learnpythonthehardway.org/tktnew Which will require an anonymous login to cut down on spam in the tickets. I'd also appreciate discussion here on the list about the approach I took with the book and what you think. Thanks for your time. Zed P.S. The book is totally free so long as you don't charge for it and you don't change it or break it up. Thanks.

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About __class__ of an int literal
by AlexWalk Sept. 29, 2010

Sept. 29, 2010

In python 3.1.2(I'm using windows edition, 32bit), accessing __class__ of an int literal will raise a SyntaxException, while other literals will not. For example. 1.__class__ is an error, while 1.1.__class__ runs ok. I searched the python issue tracker but failed to find relevant reports. I wonder if this is an unreported issue. Alex Lee

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function decorators
by Nick Donohue Sept. 29, 2010

Sept. 29, 2010

I came across this code just now: def time_me(function): def wrap(*arg): start = time.time() r = function(*arg) end = time.time() print "%s (%0.3f ms)" %(function.func_name, (end-start)*1000) return wrap @time_me def some_function(somearg) some_function(arg) I've been looking online about what I think is going on, and from what I can tell this code is using function decorators. I guess what I'm asking is if someone could tell me what exactly is going on in this code - how is it different from passing: time_me(some_function(123))? I've tried it this way and it works. why would I use these? wouldn't it be more flexible to not write the decorator before the function definition, so I could choose to wrap it or not? thanks

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Re: partial sums problem
by Seebs Sept. 28, 2010

Sept. 28, 2010

On 2010-09-28, Gary Herron <gherron(a)digipen.edu> wrote: > Python does have "s+=t" as a statement, and it does have list > comprehensions [... for ...] as expressions, but you cannot put a > statement inside an expression. I've inferred that, in Python, all assignments are by definition statements, rather than expressions, so they can't be arbitrarily substituted in for expressions. It's interesting to see the two ways in which people seem to go from C's middle ground of expressions and statements; some languages go to making statements into expressions, others go for even further narrowing the set of "expressions". I'm not yet sure which I prefer; both have some appeal in avoiding some of the occasional-complexity that can make C hard for people to learn. (Meaning, complexity which is only sometimes at issue, so you have to know about it, but you can't just use it all the time, so you can't assume it's how things work.) -s -- Copyright 2010, all wrongs reversed. Peter Seebach / usenet-nospam(a)seebs.net http://www.seebs.net/log/ <-- lawsuits, religion, and funny pictures http://en.wikipedia.org/wiki/Fair_Game_(Scientology) <-- get educated! I am not speaking for my employer, although they do rent some of my opinions.

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utf-8 and ctypes
by Brendan Miller Sept. 28, 2010

Sept. 28, 2010

I'm using python 2.5. Currently I have some python bindings written in ctypes. On the C side, my strings are in utf-8. On the python side I use ctypes.c_char_p to convert my strings to python strings. However, this seems to break for non-ascii characters. It seems that characters not in the ascii subset of UTF-8 are discarded by c_char_p during the conversion, or at least they don't print out when I go to print the string. Does python not support utf-8 strings? Is there some other way I should be doing the conversion? Thanks, Brendan

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Re: Upload files with wsgi
by John Nagle Sept. 28, 2010

Sept. 28, 2010

On 9/28/2010 3:31 PM, Hidura wrote: > Hello, i have a project on Python3k, and i have a very big problem i > don' t find how take an upload file i am using the wsgiref lib, and or > theres any way to connect to the client in order to get the file by > myself? > > Thank you > Diego Hidalgo. This is not clear. Are you trying to upload a Python program to a server, where a web server will run it in response to web requests? Or what? Does this involve an Apache server? John Nagle

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Upload files with wsgi
by Hidura Sept. 28, 2010

Sept. 28, 2010

Hello, i have a project on Python3k, and i have a very big problem i don' t find how take an upload file i am using the wsgiref lib, and or theres any way to connect to the client in order to get the file by myself? Thank you Diego Hidalgo. -- Enviado desde mi dispositivo móvil Diego I. Hidalgo D.

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JSONBOT 0.4 RELEASED
by Bart Thate Sept. 28, 2010

Sept. 28, 2010

Yesterday i pushed version 0.4 of JSONBOT to pypi and googlecode. This version has a rewritten core that makes it easier to develop bots for and has lots of bugs fixed. A karma plugin was added as well as a silent mode that forwards bot responses to /msg. You can grab a copy on http://jsonbot.googlecode.com or use the mercurial reposistory: "hg clone http://jsonbot.googlecode.com/hg jsonbot". please file any bugs reports at http://code.google.com/p/jsonbot/issues/list we are at #dunkbots on freenode and IRCnet. Have fun ! about JSONBOT: JSONBOT is a remote event-driven framework for building bots that talk JSON to each other over XMPP. IRC/Console/XMPP (shell) Wave/Web/XMPP (GAE) implementations provided.

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Pyro 4.2 released
by Irmen de Jong Sept. 28, 2010

Sept. 28, 2010

Pyro 4.2 --------- I'm pleased to announce the release of Pyro 4.2! Detailed info here: http://www.razorvine.net/python/Pyro Download here: http://www.xs4all.nl/~irmen/pyro4/download/ Python package index entry: http://pypi.python.org/pypi/Pyro4 License: MIT software license. Note: Pyro 4 is not finalized, this is still a beta release. Changes ------- The most important changes compared to Pyro 4.1 are: - toplevel package renamed to Pyro4 to allow parallel installation of Pyro 3.x and Pyro4 - python 3.x compatibility What is Pyro? ------------- PYthon Remote Objects provides a very easy way of remote communication between python objects somewhere in a network. It enables you to do remote method calls on objects as if they were normal local objects. Objects can be located by a direct identifier or indirectly by logical, humanly-readable names that are managed in a name server. Pyro is designed to be simple (but powerful) so it's only a manner of adding a few lines of code to ignite your objects. Simple example: http://www.razorvine.net/python/Pyro/Example Enjoy, Irmen de Jong

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Re: list problem...
by Shashwat Anand Sept. 28, 2010

Sept. 28, 2010

On Wed, Sep 29, 2010 at 1:15 AM, rog <rog(a)pynguins.com> wrote: > Shashwat Anand wrote: > > >> >> On Wed, Sep 29, 2010 at 12:14 AM, Rog <rog(a)pynguins.com <mailto: >> rog(a)pynguins.com>> wrote: >> >> Hi all, >> Have been grappling with a list problem for hours... >> a = [2, 3, 4, 5,.....] >> b = [4, 8, 2, 6,.....] >> Basicly I am trying to place a[0], b[0] in a seperate list >> IF a[2] and b[2] is present. >> >> >> You are not exactly clear with your problem statement. >> Care to elaborate it more. >> >> I have tried sets, zip etc with no success. >> I am tackling Euler projects with Python 3.1, with minimal >> knowledge, and having to tackle the language as I progress. >> Enjoyable frustration :) >> >> -- >> Rog >> http://www.rog.pynguins.com >> -- >> http://mail.python.org/mailman/listinfo/python-list >> >> >> >> >> -- >> ~l0nwlf >> > > "Let d(/n/) be defined as the sum of proper divisors of /n/ (numbers less > than /n/ which divide evenly into /n/). > If d(/a/) = /b/ and d(/b/) = /a/, where /a/ ≠ /b/, then /a/ and /b/ are an > amicable pair and each of /a/ and /b/ are called amicable numbers. > > For example, the proper divisors of 220 are 1, 2, 4, 5, 10, 11, 20, 22, 44, > 55 and 110; therefore d(220) = 284. The proper divisors of 284 are 1, 2, 4, > 71 and 142; so d(284) = 220. > > Evaluate the sum of all the amicable numbers under 10000." > > from Project Euler. > I have all answers contained in two lists but need to extract the amicable > pairs. > eg > a = [200, 4, 284,.....] > b = [284, 9, 200, ......] > Hope that helps. > Thanks for the link. > I am not sure how and what you managed, but what I understand you need to calculate sum of divisors. A quick unoptimized solution can be, >>> def divsum(n):return sum(i for i in range(1, n) if not n % i)... >>> divsum(220)284>>> divsum(284)220 Now all is left is looping and little maths, since upper bound is not high, brute force is Ok. <spoiler> http://codepad.org/g6PRyoiV </spoiler> # For reference Also I guess you missed 'Reply All', please take care of it next time. > Rog > > -- ~l0nwlf

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