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

Re: List problem
by User Nov. 2, 2004

Nov. 2, 2004

On Fri, 29 Oct 2004 17:52:03 +0000 (UTC), Steven Bethard <steven.bethard(a)gmail.com> wrote: >Thomas M. <thomas.sunshine <at> web.de> writes: >> >> test_list = [1, 2, 3] >> >> for i in test_list: >> print i >> >> if 1 in test_list: >> test_list.remove(1) >> >> Why is the second item not print ? > >Maybe this will help illustrate the problem: > >>>> test_list = [1, 2, 3] >>>> for i, item in enumerate(test_list): >... print item >... print "start", i, test_list[i], test_list >... if 1 in test_list: >... test_list.remove(1) >... print "end", i, test_list[i], test_list >... >1 >start 0 1 [1, 2, 3] >end 0 2 [2, 3] >3 >start 1 3 [2, 3] >end 1 3 [2, 3] > >On the first iteration of the loop, you are looking at item 0 in a 3-item list, >[1, 2, 3]. When you remove 1 from the list, you convert the 3-item list into a >2-item list, thust shifting the indices down, so that test_list[0] is now 2. >When the for loop continues, it is now looking at index 1, and the item at index >1 in your (adjusted) 2-item list is 3. > >In general, removing elements from a list while you're iterating though the list >is a bad idea. Perhaps a better solution is a list comprehension: Unless you're using a while loop and iterating in reverse, for example: a = [0,1,2,3,4] pos_max = len(a) - 1 # Maximum iterable element pos = pos_max # Current element while pos >= 0: if a[pos] == 2: a.remove(2) pos_max = pos_max - 1 pos = pos - 1 > >>>> test_list = [1, 2, 3] >>>> [x for x in test_list if x != 1] >[2, 3] >>>> for item in [x for x in test_list if x != 1]: >... print item >... >2 >3 > >Steve

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ruby on rails ... python on ?
by flab ba Nov. 2, 2004

Nov. 2, 2004

The pragmatic programmers (Dave & Andy) are spreading a good word about RubyOnRails. I was wondering if there are any Python programmers who are /also/ familiar with Rails - and if they could recommend something in the Python world that is comparable. -Flab

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Re: Method Underscores?
by Chris S. Nov. 2, 2004

Nov. 2, 2004

Josiah Carlson wrote: > Double underscore methods are considered "magic" methods. The > underscores are a hint that they may do something different. Kind of > like the C++ friend operators. > > In terms of .len() vs .__len__(), it is not supposed to be called > directly by user code; __len__() is called indirectly by the len() > builtin (and similarly for the other __<op>__() methods, check common > spellings in the operator module). I realize that. My point is why? Why is the default not object.len()? The traditional object oriented way to access an object's attribute is as object.attribute. For those that are truly attached to the antiquated C-style notation, I see no reason why method(object) and object.method() cannot exist side-by-side if need be. Using method(object) instead of object.method() is a throwback from Python's earlier non-object oriented days, and something which should be phased out by p3k. Personally, I'd like to see the use of underscores in name-mangling thrown out altogether, as they "uglify" certain code and have no practical use in a truly OO language, but I'm sure that's a point many will disagree with me on.

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[wx] Simple image editor
by Michele Petrazzo Nov. 2, 2004

Nov. 2, 2004

I want to create a simple image editor (with wxPython) for my application. Now I'm able to zoom, draw with a pen, insert a text into the loaded image, and undo changes (for this I reload the image and redraw all the lines/text, but not the last.) My problem is how can I move the texts/lines that are insert into Image, after placed? How the image editors (like GIMP) are able to move the objects? Please don't tell me to read the GIMP's source :). Thanks, Michele P.s. I hope you understand me, my English is horrible.

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Re: OT: Ruby programmers use Python (was Re: ruby on rails ... python on ?)
by flab ba Nov. 2, 2004

Nov. 2, 2004

On Sun, 31 Oct 2004 01:24:31 -0700, Josiah Carlson wrote: > > Peter Hansen <peter(a)engcorp.com> wrote: >> >> flab ba wrote: >> > The pragmatic programmers (Dave & Andy) are spreading a good word about >> > RubyOnRails. I was wondering if there are any Python programmers who are >> > /also/ familiar with Rails - and if they could recommend something in the >> > Python world that is comparable. >> >> I googled for that to learn about it. Saw a note in the home page >> of rubyonrails.org from Oct 11 about them having a new bug tracker >> working! >> >> "Cool," sez I, a fan of issue trackers in general, "Let's see >> what these Ruby guys have come up with for a bug tracker." >> >> It's Trac. > > You'll notice a project linked from the RubyOnRails site: Basecamp > (www.basecamphq.com), which looks quite spiffy. > > - Josiah You're right - that web site does look quite spiffy. I was deciding on Quixote for my web app framework, but even the author claims that it isn't the right framework if you think a website is a graphics design problem. I'm not a graphics designer, but I need more spiffyness than the MEMS web site - which is done in Quixote. -Alex

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Reading XML like Python!
by johng2001＠rediffmail.com Nov. 2, 2004

Nov. 2, 2004

I have to read a lot of XML for my upcoming project. XML is hard on my eyes. Is there some sort of converter that converts XML to something more eye friendly? maybe like Python? I have seen restructured text. There is a paper at EuroPython 2004 that seems to do something similar. "Pythonic Alternatives for declarative XML-based specifications of robot behavior" Anyone know of any tools along these lines? Thanks.

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Error import PyWinTypes24.dll
by alain.marcel＠svd-info.fr Nov. 2, 2004

Nov. 2, 2004

Hi all ! I'm working on Windows XP, with Python24. I've a trouble with PyWinTypes24.dll (python Windows extensions). Trouble is not due to specific python version 24. To distribute my applications, I don't want to put anything else elsewhere (neither in Windows/System32 nor in registry). So I deliver a folder (says HOME) that contains two mains folders - a folder Python24 that contains python distribution and msvcr71.dll, python24.dll, PyWinTypes24.dll - a folder apps that contain a folder per python application I start my python applications with such command : HOME/Python24/Python HOME/apps/app1/run.py Windows complains that it cannot found PyWinTypes24.dll. If I copy PyWinTypes24.dll in each HOME/apps/appX folder, then it works. It's a solution but not very nice. Is there a solution without duplicate PyWinTypes24.dll ? Thanks, Alain

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Linksys Router & Python
by Brad Tilley Nov. 2, 2004

Nov. 2, 2004

Probably a stupid question, but here goes: Is there any way to get a scaled down version of Python onto a Linksys Wireless router? Are there any projects out there that are doing this? I've googled around a bit, but didn't find much. I want to keep the router's software as it is, but I also would like to have some scripting abilities on it as well (like email the router's IP addy every x hours), etc. I have scripts that run on my computers that do this sort of thing. def url_open(): """ Function that gets and returns the IP addy of my Linksys BEFW11S4 Wireless DSL router.""" import urllib, re ip = re.compile ('\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}') f = urllib.urlopen("http://user:passwd@192.168.1.1/RouterStatus.htm") data = f.read() f.close() routerip = ip.findall(data) print routerip[0] return routerip[0] But, when I leave town for vacation, I don't like leaving a computer running. If I could get the interpreter embedded in the device itself, then that would solve the problem. This is probably a shot in the dark, but I thought I'd ask. Thanks, Brad

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spell checking
by dataangel Nov. 1, 2004

Nov. 1, 2004

I was just curious if there were any spell checker python modules around that can guess at what the user meant to type in. I wrote up a quick function that splices a string up into bigrams and then checks how many bigrams are identical to a given word, which I think is how google does it. But support for trigrams etc. could be added, so I'm curious if anyone out there has done something more. Here's the script: def StringsSimilarity(str1, str2): """Divides the two strings into bigrams and reports what percentage of them are equal""" str1 = str1.strip().lower() str2 = str2.strip().lower() bigramStr1 = [] bigramStr2 = [] currentList = bigramStr1 i = 0 j = 0 # Empty versus non empty strings are never similar if not (str1 and str2): return 0 # 100% match if equal if str1 == str2: return 1.0 # Make strings equal length, simplifies things len1 = len(str1) len2 = len(str2) if len1 > len2: str2 = str2 + " "*(len1-len2) elif len2 > len1: str1 = str1 + " "*(len2-len1) len1 = len(str1) len2 = len(str2) currentString = str1 # Generate bigrams while j < 2: i = 0 while i < len1: if i+1 >= len1: currentList.append(currentString[i]) else: currentList.append(currentString[i] + currentString[i+1]) i += 2 j += 1 currentList = bigramStr2 currentString = str2 similarity = 0 for i in range(len(bigramStr1)): if bigramStr1[i] == bigramStr2[i]: similarity += 1.0 if similarity == 0: return 0 return similarity/len(bigramStr1) def StringsSimilar(str1, str2): """Using StringSimilarity, decides if the two strings score is good enough, 50%, to be considered similar""" return StringsSimilarity(str1, str2) >= 0.50

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Survey of use of Python Language in Open-source / Free Music Software
by alia_khouri＠yahoo.com Nov. 1, 2004

Nov. 1, 2004

Hi, Here are the results (in no particular order) of an informal survey of open-source / free music applications which use python in some form or the other. If you know of any other other examples please add them to the list. Enjoy (-; AK ---------------------------------------------------------------------- Survey of use of Python Language in Open-source / Free Music Software ---------------------------------------------------------------------- pymps http://www.anti-particle.com/pymps.shtml Pymps is the PYthon Music Playing System - a web based mp3/ogg jukebox. It's written in Python and utilises the PostgreSQL database. m3ute2 http://sourceforge.net/projects/m3ute2/ m3ute2 is program for copying, moving, and otherwise organizing M3U playlists and directories. m3ute2 can also generate detailed reports about lists of files. fmod http://www.fmod.org/ FMOD is the fastest, most powerful and easiest to use sound system on Windows, Linux, and Windows CE there is, and now Macintosh, GameCube, PS2 & XBox!. FMOD supports 3d sound, midi, mods, mp3, ogg vorbis, wma, aiff, recording, obstruction/occlusion, cd playback (analog or digital), cd ripping, mmx, internet streaming, dsp effects, spectrum analysis, user created samples and streams, synchronization support, ASIO, EAX 2&3, C/C++/VB/Delphi and more. pysonic http://pysonic.sourceforge.net/ pySonic is a Python wrapper around the high performance, cross platform FMOD sound library. You get all the benefits of the FMOD library, but in a Pythonic, object oriented package. PMIDI http://sourceforge.net/projects/uncassist The PMIDI library allows the generation of short MIDI sequences in Python code.The interface allows a programmer to specify songs, instruments, measures, and notes. Playback is handled by the Windows MIDI stream API so proper playback timing is handled by the OS rather than by client code. The library is especially useful for generating earcons. PythonMIDI http://www.mxm.dk/products/public/pythonmidi The Python Midi package is a collection of classes handling Midi in and output in the Python programming language. PythonSound http://pythonsound.sourceforge.net/ The Python Sound Project aims to develop a productive community around Python, Csound and other synthesis engines as tools for algorithmic and computer assisted composition of electroacoustic music. AthenaCL http://www.flexatone.net/athena.html AthenaCL is an open-source, cross-platform, command-line program that functions as both a pitch (class) set theory utility (capable of both set and voice-leading modeling and analysis) as well as an object-orientated, Python-scriptable algorithmic front-end to Csound. Combining these features allows rapid and flexible scoring of Csound instruments with the elegance of Python-written texture algorithms. These simple algorithms allow the organization of pitch-materials by ordered content-groups, employing 12-tone set-class and pitch-class notations. Rather than writing its own music, AthenaCL is a compositional assistant: the algorithms create complex textural surfaces, leaving the limitless mixture and placement of these textures and their attributes entirely in the hands of the composer. PyJack http://www.a2hd.com/software/ This is a Python C extension module which provides an interface to the Jack Audio Server. It is possible to access the Jack graph to perform port connections/disconnections, monitor graph change events, and to perform realtime audio capture and playback using Numeric Python arrays. This is released under the GPL. Csound / CsoundVST http://www.csounds.com/ Csound is a programming language designed and optimized for sound rendering and signal processing. The language consists of over 450 opcodes - the operational codes that the sound designer uses to build "instruments" or patches. Although there are an increasing number of graphical "front-ends" for the language, you typically design and modify your patches using a word processor. Usually, you create two text files - a .orc (orchestra) file containing the "instruments," and a .sco (score) file containing the "notes." In Csound, the complexity of your patches is limited by your knowledge, interest, and need, but never by the language itself. For instance, a 22,050 oscillator additive synthesizer with 1024 stage envelope generators on each is merely a copy-and-paste operation. The same goes for a 1 million voice granular texture! Have you ever dreamed of sounds such as these? Well in Csound you can. And in Csound these dreams can come true! dublin http://seqdublin.sourceforge.net/ Dublin is an object oriented framework to generate events in pd. Every objects is defined in python and then it interacts with other objects in pure-data. The goal is not only the provide an external python facility to pd but also to give the functionality of a sequencer. As for the user interface, it uses Idle, the Python IDE to edit and run event scripts. MusicKit http://musickit.sourceforge.net/ The MusicKit is an object-oriented software system for building music, sound, signal processing, and MIDI applications. It has been used in such diverse commercial applications as music sequencers, computer games, and document processors. Professors and students in academia have used the MusicKit in a host of areas, including music performance, scientific experiments, computer-aided instruction, and physical modeling. Using the Python to Objective C bridge PyObjC enables applications and utilities to be written in Python, an interpreted object-oriented language. GNU Solfege http://solfege.org/ GNU Solfege is a computer program written to help you practice ear training.It can be useful when practicing the simple and mechanical exercises. Snack http://www.speech.kth.se/snack/ The Snack Sound Toolkit is designed to be used with a scripting language such as Tcl/Tk or Python. Using Snack you can create powerful multi-platform audio applications with just a few lines of code. Snack has commands for basic sound handling, such as playback, recording, file and socket I/O. Snack also provides primitives for sound visualization, e.g. waveforms and spectrograms. It was developed mainly to handle digital recordings of speech, but is just as useful for general audio. Snack has also successfully been applied to other one-dimensional signals. The combination of Snack and a scripting language makes it possible to create sound tools and applications with a minimum of effort. This is due to the rapid development nature of scripting languages. As a bonus you get an application that is cross-platform from start. It is also easy to integrate Snack based applications with existing sound analysis software. Pygame http://pygame.org/ Pygame is a set of Python modules designed for writing games. It is written on top of the excellent SDL library. This allows you to create fully featured games and multimedia programs in the python language. Pygame is highly portable and runs on nearly every platform and operating system. Pyper http://www.stanford.edu/~andyszy/pyper/ Pyper is a musical development environment. It allows you to write Python scripts that generates music in real-time. Pyper uses QuickTime Musical Instruments for synthesis.

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