[ANN] Leipzig Python User Group - Meeting, March 11, 2008, 08:00pm
=== Leipzig Python User Group === We will meet on Tuesday, March 11 at 8:00 pm at the training center of Python Academy in Leipzig, Germany ( http://www.python-academy.com/center/find.html ). Our main topic will be the Chemnitzer Linux-Tage. Our booth was pretty busy. Quite a few people were really interested in our user group. Many of us were there as presenters and/or helpers at booths of other projects. Therefore, there will be lots things to talk about such as visited presentations, talks at booths, or impressions. Food and soft drinks are provided. Please send a short confirmation mail to [EMAIL PROTECTED], so we can prepare appropriately. Everybody who uses Python, plans to do so or is interested in learning more about the language is encouraged to participate. While the meeting language will be mainly German, we will provide English translation if needed. Current information about the meetings are at http://www.python-academy.com/user-group . Mike == Leipzig Python User Group === Wir treffen uns am Dienstag, 11.03.2008 um 20:00 Uhr im Schulungszentrum der Python Academy in Leipzig ( http://www.python-academy.de/Schulungszentrum/anfahrt.html ). Wir wollen über die Chemnitzer Linux-Tage sprechen. Unseren Stand war recht gut besucht und wir haben doch Einige für die User Group interessieren können. Viele von uns waren als Vortragende und/oder Mitwirkende an anderen Ständen dort. So gibt es sicher viel über besuchte Vorträge, Gespräche und Eindrücke mitzuteilen. Für das leibliche Wohl wird gesorgt. Eine Anmeldung unter [EMAIL PROTECTED] wäre nett, damit wir genug Essen besorgen können. Willkommen ist jeder, der Interesse an Python hat, die Sprache bereits nutzt oder nutzen möchte. Aktuelle Informationen zu den Treffen sind unter http://www.python-academy.de/User-Group zu finden. Viele Grüße Mike -- http://mail.python.org/mailman/listinfo/python-announce-list Support the Python Software Foundation: http://www.python.org/psf/donations.html
Have Your City Host PyCon 2010!
The PyCon organizers are excited to announce the start of the PyCon 2010 planning process! Even more importantly, we're looking for motivated local groups to spearhead this volunteer-run, community-based conference. In years past, the locale for the next year was arranged about a year in advance. That worked while we were a smaller conference with many venues to choose from. PyCon 2008, to be held soon in the Chicago area, has over 950 registered attendees at this time. That is over one and a half times the number of attendees from just the year before! We're excited to see PyCon grow, but it also means that how we plan PyCon needs to change just a little bit. The first change is a change in the timeline. Starting with PyCon 2010, we're aiming to begin planning two years ahead. To help us do that, PyCon 2009 will also be held in the Chicago area, at the same venue as 2008. The second change is that the bid process will not be as detail-heavy and will not demand as much initial work by local groups. Instead, we're focusing on the heart and soul of PyCon: the community of volunteers -- we're looking to find excited and committed groups who want to be the backbone of PyCon 2010. The details will be worked out in a collaborative process, with local groups working in conjunction the volunteer PyCon organizers and the Python Software Foundation's Conference Committee. Still interested? Curious? Do you want PyCon 2010 hosted in your area? Here's what to do: • Form a group of people interested in helping with the conference planning. • If you're attending PyCon 2008, join us for a kick-off meeting over lunch on Saturday, March 15th. • Make sure at least one person from your group is on the PyCon organizer's list[1] and, as soon as possible, announce your interest in submitting a bid on the list. This process should be viewed as cooperative -- we're here to help and encourage any group that wants to take on hosting PyCon. • Finally, assemble your official bid, referring to the PyCon Bid Guidelines [2] for information and deadlines and submit it to the PyCon organizer's list before the deadline listed in the PyCon Bid Guidelines. Posting your bid to a publicly viewable website wouldn't be a bad idea either... If you have any questions or need any help, feel free to email the organizer's list and ask away! [1] http://mail.python.org/mailman/listinfo/pycon-organizers [2] http://wiki.python.org/moin/PyConPlanning/BidRequirements -- http://mail.python.org/mailman/listinfo/python-announce-list Support the Python Software Foundation: http://www.python.org/psf/donations.html
ANN: PyTables 2.0.3 released
=== Announcing PyTables 2.0.3 === PyTables is a library for managing hierarchical datasets and designed to efficiently cope with extremely large amounts of data with support for full 64-bit file addressing. PyTables runs on top of the HDF5 library and NumPy package for achieving maximum throughput and convenient use. This is a maintenance release that mainly fixes a couple of important bugs (bad update of multidimensional columns in table objects, and problems using large indexes in 32-bit platforms), some small enhancements, and most importantly, support for the latest HDF5 1.8.0 library. Also, binaries have been compiled against the latest stable version of HDF5, 1.6.7, released during the past February. Thanks to the broadening PyTables community for all the valuable feedback. In case you want to know more in detail what has changed in this version, have a look at ``RELEASE_NOTES.txt``. Find the HTML version for this document at: http://www.pytables.org/moin/ReleaseNotes/Release_2.0.3 You can download a source package of the version 2.0.3 with generated PDF and HTML docs and binaries for Windows from http://www.pytables.org/download/stable/ For an on-line version of the manual, visit: http://www.pytables.org/docs/manual-2.0.3 Migration Notes for PyTables 1.x users == If you are a user of PyTables 1.x, probably it is worth for you to look at ``MIGRATING_TO_2.x.txt`` file where you will find directions on how to migrate your existing PyTables 1.x apps to the 2.x versions. You can find an HTML version of this document at http://www.pytables.org/moin/ReleaseNotes/Migrating_To_2.x Resources = Go to the PyTables web site for more details: http://www.pytables.org About the HDF5 library: http://hdfgroup.org/HDF5/ About NumPy: http://numpy.scipy.org/ To know more about the company behind the development of PyTables, see: http://www.carabos.com/ Acknowledgments === Thanks to many users who provided feature improvements, patches, bug reports, support and suggestions. See the ``THANKS`` file in the distribution package for a (incomplete) list of contributors. Many thanks also to SourceForge who have helped to make and distribute this package! And last, but not least thanks a lot to the HDF5 and NumPy (and numarray!) makers. Without them, PyTables simply would not exist. Share your experience = Let us know of any bugs, suggestions, gripes, kudos, etc. you may have. -- 0,0 Francesc Altet http://www.carabos.com/ V V Cárabos Coop. V. Enjoy Data - -- http://mail.python.org/mailman/listinfo/python-announce-list Support the Python Software Foundation: http://www.python.org/psf/donations.html
Re: Regarding coding style
On Fri, 07 Mar 2008 20:57:32 -0800, dave_mikesell wrote: x = get_stuff(store) # Get the stuff what was brought at the store. Perfect example of an unnecessary comment. The variable and function names are commentary enough. x is a terrible name. What does it mean? Nothing. There's only three places x is an appropriate name: (1) A meta-syntactic variable like foo, bar, spam, ham, parrot. (2) Library functions, where x stands for a generic argument, usually a number, e.g. def sin(x). (3) Throw-away code you don't need to maintain. The function name also doesn't explain anything. How was the stuff got? Was it paid for, or stolen, or picked up on consignment, or what? Compare the above line with: x = get_stuff(store) # Steal stuff from the store. or x = get_stuff(store) # Pickup the stuff from the store for disposal. # The amount paid by the store is stored in global variable pay_received # and the name of the employee authorizing the pickup is stored in the # global authorized_by. But even if you were right that the comment was unnecessary, you have missed my point that even single sentences can be grammatically bogus and the writer could learn a lot from Strunk and White or equivalent. (Often the writer will learn bad habits, but at least they'll be grammatically correct bad habits.) -- Steven -- http://mail.python.org/mailman/listinfo/python-list
Re: Want - but cannot get - a nested class to inherit from outer class
On Mar 7, 7:46 pm, DBak [EMAIL PROTECTED] wrote: However I can't do this, because, of course, the name Tree isn't available at the time that the classes _MT and _Node are defined, so _MT and _Node can't inherit from Tree. Not only is the name not defined, the class doesn't even exist yet. Yes, but, well - it certainly isn't usable yet, but some object (that will be the class when it is finished) is being built (its __dict__ is being populated, etc.) - so there's an object pointer available inside the interpreter that could be put somewhere. But this is pedantic - you're right, the class really isn't available until after the class statement. There is no obvious solution-- What do you mean? If there are any at all, there is significant competition without clear winners. dict dictA: membA= 0 membB= 0 dict dictB: membC= 0 Thanks for your answer. To the extent I understand it: There is a difference between the class statements I was trying to nest, with the inner inheriting from the outer, and your dict example. The main thing is that in the class example - when the inner class is being built (i.e., inside its class statement's block) there is no need (as I understand it) for the parent class to be functional at all WHILE I AM DEFINING METHODS on the inner class. Sure, if the inner class had An interesting observation. But in the case I'm talking about I just want to define methods on the inner class, using names such that when the method is eventually called on an instance of the inner class the attribute lookup will proceed with the outer class being the inner class' parent. Creating There are two possibilities I'm thinking of. In both, cases you go back after Tree is finished executing, and inform _Node and _MT of their parentage. I haven't tested either. The first is, define a metaclass that allows __mro__ (method resolution order) to be written to. But does the look-up get performed on the one you define? The second is, cache _Node and _MT during creation, and go back and reinstantiate them. class Tree(object): ...class _MT( metaclass= placeholder ): ..def isEmpty(self): return True ..def insert(self, X): return Tree._Node(X) ...class _Node( metaclass= placeholder ): ..def isEmpty(self): return False ..def insert(self, X): return _Node(X, self, Tree._MT()) ...def __init__(): return _MT() ...def merge(self, T): ..code for merging tree T into self Tree._MT.complete( Tree ) Tree._Node.complete( Tree ) And similarly, class Tree(object): @placeholder ...class _MT(): ..def isEmpty(self): return True ..def insert(self, X): return Tree._Node(X) @placeholder ...class _Node( metaclass= placeholder( Tree ) ): ..def isEmpty(self): return False ..def insert(self, X): return _Node(X, self, Tree._MT()) ...def __init__(): return _MT() ...def merge(self, T): ..code for merging tree T into self Tree._MT.complete( Tree ) Tree._Node.complete( Tree ) Here the last lines might read: Tree._MT= Tree._MT.complete( Tree ) Tree._Node= Tree._Node.complete( Tree ) But maybe not. Here's a third, actually: class Tree( placeholder ): pass class Tree(object, metaclass= placeholderreplace( Tree ) ): ...class _MT(Tree): ..def isEmpty(self): return True ..def insert(self, X): return Tree._Node(X) ...class _Node(Tree): ..def isEmpty(self): return False ..def insert(self, X): return _Node(X, self, Tree._MT()) ...def __init__(): return _MT() ...def merge(self, T): ..code for merging tree T into self If you're using Python -3.0, you might even be able to get away without metaclasses on the first one, or decorators on the second one: class Tree(object): ...class _MT(): ..def isEmpty(self): return True ..def insert(self, X): return Tree._Node(X) _MT= placeholder( _MT ) ...class _Node( metaclass= placeholder( Tree ) ): ..def isEmpty(self): return False ..def insert(self, X): return _Node(X, self, Tree._MT()) _Node= placeholder( _Node ) ...def __init__(): return _MT() ...def merge(self, T): ..code for merging tree T into self Tree._MT.complete( Tree ) Tree._Node.complete( Tree ) And once again I'm still not sure. -- http://mail.python.org/mailman/listinfo/python-list
Re: Timed execution in eval
On Mar 7, 9:43 pm, George Sakkis [EMAIL PROTECTED] wrote: On Mar 7, 11:12 am, [EMAIL PROTECTED] wrote: I have various bits of code I want to interpret and run at runtime in eval ... Check out these two recipes: - Using signals:http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/307871 - Using threads:http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/483752 the second can't interrupt code that doesn't release the GIL and doesn't actually kill the function after the timeout. Mine doesn't either, plus you need a C compiler. I also learned today that one of the import statements doesn't find the dll on Py 3.0. Do you have a process kill ability? That's another way to do it. -- http://mail.python.org/mailman/listinfo/python-list
Re: help on file storage for split multi part download
On Mar 7, 2:14 pm, Gabriel Genellina [EMAIL PROTECTED] wrote: En Fri, 07 Mar 2008 04:16:42 -0200, [EMAIL PROTECTED] escribi�: On Mar 7, 1:38 am, Gabriel Genellina [EMAIL PROTECTED] wrote: En Thu, 06 Mar 2008 14:34:27 -0200, [EMAIL PROTECTED] escribi�: storage class which can write the file splits that are currently being downloaded to the disk. this is exactly what otherdownload accelerators do, i guess. Uh, unless I misundersand you, a standard file object is enough. First create a file with the required size (open(...,'wb'), seek(n-1), write(chr(0))). For each downloaded chunk you have to know its position in the file; then just seek() and write() it. BUT the thing thats going in my mind is thread safety. i plan to start each part of the filedownloadin a different thread. and then when each thread had downloaded more than 100kb (or eof or boundary reached) write the buffer to the disk. can this be achieved using mutex ? i have never shared objects between threads. Use a different (single) thread to write the file; the others put write requests on a Queue.queue object, and the writer just gets the requests and processes them. is there a way to write this without using threads at all ??? Using asyncore, and perhaps the Twisted framework. -- Gabriel Genellina asyncore is basically a server thing right? -- http://mail.python.org/mailman/listinfo/python-list
Re: distutils - Is is possible to install without the .py extensions
* Fri 2008-03-07 Robert Kern [EMAIL PROTECTED] gmane.comp.python.general * Message-Id: [EMAIL PROTECTED] setup(name='program', ... scripts = ['program,py'], ) that the the result is: /usr/bin/program instead of: /usr/bin/program.py The easiest and best way is to just rename the file in your source tree to program and be done with it. Is there any other way? This is the source package that I would like to keep intact and just patch the setup.py Not really, no. Why is it so important to only patch the setup.py file and not any others? It has to do with generating a diff against the original package. If the file is moved: mv file.py file prior setup.py run (which, according to answers, would have a change to scripts = ['program']), the problem is the generated diff against original sources: + would flag removal of 'file.py' + inclusion of 'file' The ideal would be if setup.py could do all the destination install postwork. The generated patch would be clean and only contain changes in setup.py. But I understand, if distutils does not support stripping the extensions during install. It just cacuses exra work for utility packagers. Jari -- Welcome to FOSS revolution: we fix and modify until it shines -- http://mail.python.org/mailman/listinfo/python-list
Re: islice == [::]
George Sakkis: I had posted some time ago an OO wrapper of itertools; slice notation for islice was one motivation:http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/498272 I think I did see that, but later I forgot of it. It looks nice. Thank you, bearophile -- http://mail.python.org/mailman/listinfo/python-list
Re: Timed execution in eval
2008/3/7, Steven D'Aprano [EMAIL PROTECTED]:
On Fri, 07 Mar 2008 08:12:38 -0800, alex.pedwysocki wrote:
I have various bits of code I want to interpret and run at runtime in
eval ...
I hope that code doesn't contain any data coming from an untrusted user.
I want to be able to detect if they fail with error,
That's what try...except blocks are for.
try:
x = eval('1 + 1 = 2')
except SyntaxError:
x = 3
I want to be able to time them,
That's what the timeit module is for.
If you do time them, you will find that eval(expr) is MUCH MUCH slower
than just executing expr as normal.
from timeit import Timer
Timer('1+1').timeit()
0.25557518005371094
Timer('eval(1+1)').timeit()
21.816912174224854
If you use eval() a lot, you will have a SLOW program.
and I want to be able to stop them if they run too long.
That's tricky. As far as I know, the only way for a Python program to
stop an arbitrary calculation after a certain period of time it to run it
in a thread. You then monitor the elapsed time, and when the timer
expires, ask the thread to die. And hope it listens.
Or you could use setitimer (not available for now). I opened an issue
at roundup to add setitimer and getitimer wrappers to the signal
module.
It would be great if you could test on your platform. It was done for
py3k, but could easily be back ported to python 2.6.
http://bugs.python.org/issue2240
I cannot add code to the eval'd strings that will help me accomplish
this.
You can't? Why ever not?
Note: that's almost certainly the wrong way to solve your problem, but
I'm curious as to why you can't.
--
Steven
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--
-- Guilherme H. Polo Goncalves
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parralel downloads
Hi, I would like to write a python script that will download a list of files (mainly mp3s) from Internet. For this, I thought to use urllib, with urlopen(myUrl).read() and then writing the resulting string to a file my problem is that I would like to download several files at the time. As I have not much experience in programming, could you point me the easier ways to do this in python ? Thanks, JD -- http://mail.python.org/mailman/listinfo/python-list
Writing Memory to File
Hi, I'm trying to do some memory analyzing stuff, i wrote me a small .c so far to dump the memory to a file for later analysis, the analyzing part itself is python code. I wonder if any of you has an idea how to dump the whole memory in Linux/Windows from python ? Using the .c for this somehow doesn't look right and comfy ;-) Regards, Stefan -- http://mail.python.org/mailman/listinfo/python-list
Re: Want - but cannot get - a nested class to inherit from outer class
Everybody has already explained why this doesn't work and a possible solution using metaclasses was suggested. I tried to implement it, ended up with monkey-patching __bases__, which is certainly an abomination (will it be possible in python 3.0?) but seems to do the trick. class _InheritFromOuterClass(object): This class is used as a marker. pass class MetaFixInheritance(type): This metaclass, along with ordinary class creation, changes base of all the inner classes (marked as inheriting from _InheritFromOuterClass) to the class being created. def __new__(self, name, bases, members): result = type(name, bases, members) for member in members.itervalues(): if isinstance(member, type) and issubclass(member, _InheritFromOuterClass): member.__bases__ = result, return result class Outer(object): Test an inner class inheriting from the outer class. Inheritance is monkey-patched upon creation of the outer class. __metaclass__ = MetaFixInheritance class Inner(_InheritFromOuterClass): pass def foo(self): return 'Outer.foo()' inner = Outer.Inner() print 'Inner.foo() is in fact', inner.foo() -- http://mail.python.org/mailman/listinfo/python-list
Re: DOM parsing not working!
Quoting Mike D [EMAIL PROTECTED]:
Hello, I've spent the morning trying to parse a simple xml file and have the
following:
import sys
from xml.dom import minidom
doc=minidom.parse('topstories.xml')
items = doc.getElementsByTagName(item)
text=''
for i in items:
t = i.firstChild
print t.nodeName
if t.nodeType == t.TEXT_NODE:
print TEXT_NODE
print t.nodeValue
text += t.data
print text
I can't figure out how to print the text value for a text node type. There
must be something obvious I'm missing, any suggestions?
Yes quite a trivial thing. t is assigned to the first child node of item
which, in your example, is a text node containg just a newline.
It will be shown if you replace your print statements with something like:
print 't.nodeValue:', t.nodeValue, '### end of t.nodeValue'
...
print 'text:', text, '### end of text'
What is that you're trying to do? Do you want to extract all text nodes inside
item?
RB
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Re: os.chdir
Quoting Maryam Saeedi [EMAIL PROTECTED]: I have a problem using os.chdir on linux. What should I do if I want to change to root directory? The below does not work: os.chdir(~/dir1) It is not mentioned in the documentation but I'm pretty sure os.dir() doesn't do tilde expansion since this is usually performed by a shell. You should use instead: os.chdir(os.join(os.environ['HOME'], 'dir1')) Cheers, RB -- http://mail.python.org/mailman/listinfo/python-list
Re: os.chdir
os.chdir(~/dir1) It is not mentioned in the documentation but I'm pretty sure os.dir() doesn't do tilde expansion since this is usually performed by a shell. You should use instead: os.chdir(os.join(os.environ['HOME'], 'dir1')) Or os.chdir(os.path.expanduser(~/dir1)) Regards, Martin -- http://mail.python.org/mailman/listinfo/python-list
List as FIFO in for loop
Hi everyone, I have an algorithm in which I need to use a loop over a queue on which I push values within the loop, sort of: while not(q.empty()): x = q.get() #process x to get zero or more y's #for each y: q.put(y) The easiest thing I can do is use a list as a queue and a normal for loop: q = [a, b, c] for x in q: #process x to get zero or more y's q.append(y) It makes me feel kind of uncomfortable, though it seems to work. The question is: is it guaranteed to work, or does Python expect that you wouldn't change the list in the loop? Regards, Muhammad Alkarouri -- http://mail.python.org/mailman/listinfo/python-list
Re: os.chdir
Quoting Martin v. Löwis [EMAIL PROTECTED]: os.chdir(~/dir1) It is not mentioned in the documentation but I'm pretty sure os.dir() doesn't do tilde expansion since this is usually performed by a shell. You should use instead: os.chdir(os.join(os.environ['HOME'], 'dir1')) Or os.chdir(os.path.expanduser(~/dir1)) Well... duh! Thanks for reminding me. Cheers, RB -- http://mail.python.org/mailman/listinfo/python-list
Re: Regarding coding style
On Mar 8, 2:38 am, Steven D'Aprano [EMAIL PROTECTED] cybersource.com.au wrote: On Fri, 07 Mar 2008 20:57:32 -0800, dave_mikesell wrote: x = get_stuff(store) # Get the stuff what was brought at the store. Perfect example of an unnecessary comment. The variable and function names are commentary enough. x is a terrible name. What does it mean? Nothing. Right, that's a problem with the code. A comment only masks the bad smell. 'x' should be renamed to something meaningful, obviating the need for comments to follow it around. There's only three places x is an appropriate name: (1) A meta-syntactic variable like foo, bar, spam, ham, parrot. (2) Library functions, where x stands for a generic argument, usually a number, e.g. def sin(x). (3) Throw-away code you don't need to maintain. I use single letter variables where their scope is very small. e.g., tight loops, small functions, etc. I even use them as class members where they make sense in the domain. x, y, z for 3d vectors, r, g, b, a for colors, etc. The function name also doesn't explain anything. How was the stuff got? Was it paid for, or stolen, or picked up on consignment, or what? Compare the above line with: x = get_stuff(store) # Steal stuff from the store. or x = get_stuff(store) # Pickup the stuff from the store for disposal. # The amount paid by the store is stored in global variable pay_received # and the name of the employee authorizing the pickup is stored in the # global authorized_by. Shouldn't get_stuff's comment be with its definition? And just rename the function to something more meaningful, like purchase_goods(store), or whatever. But even if you were right that the comment was unnecessary, you have missed my point that even single sentences can be grammatically bogus and the writer could learn a lot from Strunk and White or equivalent. I do agree with that 100%. It's a chore reading design and requirements docs where I work. My problem is with excessive comments. Comments are pathological liars. They almost invariably fall out of date with the code. -- http://mail.python.org/mailman/listinfo/python-list
Re: for-else
The idea of the if-else is: . depending on some condition either do this or do something else, . don't do them both. If you approach a loop-else with this same idea, you get: . depending on the loop conditions either do the loop, . or do something else, but not both. However the loop-else really works more like this: . try to do the loop; . if it starts but is interrupted by a break, . then do something else as well. So they are completely different beasts, and if you try to use or explain the one according to the rules of the other one, you put a serious strain on your synapses. The explanation that the if-else and the loop-else follow the same pattern, runs more or less like this: . all conditions to run the loop to its completion were met, . which means that the loop-condition is not met (any more), . which means that we must do something else. For me that is orwellian logic: success is failure. The loop-else mechanism is not an easy one: earlier in this thread Carl Banks turned it into an either/or construct by omitting the crucial break; Jeffrey Barish initially found the loop-else surprising; Sion Arrowsmith found it comprehensible only after some hard thinking (as in the last paragraph). The culprit is of course the keyword, else. The idea of an easy follow-up after a loop is a good one. But we need other keywords, I think at least three of them: . skipped - the loop did not run at all . broken - the loop was interrupted (by a break) . exhausted - the loop ran to completion. The last two as suggested by Laurence Tratt in his Convergence. e -- Egbert Bouwman - Keizersgracht 197 II - 1016 DS Amsterdam - 020 6257991 -- http://mail.python.org/mailman/listinfo/python-list
Re: List as FIFO in for loop
malkarouri schreef: Hi everyone, I have an algorithm in which I need to use a loop over a queue on which I push values within the loop, sort of: while not(q.empty()): x = q.get() #process x to get zero or more y's #for each y: q.put(y) The easiest thing I can do is use a list as a queue and a normal for loop: q = [a, b, c] for x in q: #process x to get zero or more y's q.append(y) It makes me feel kind of uncomfortable, though it seems to work. The question is: is it guaranteed to work, or does Python expect that you wouldn't change the list in the loop? Changing a loop while iterating over it is to be avoided, if possible. In any case, a deque is more efficient for this kind of use. I'd use it like this: from collections import deque q = deque([a, b, c]) while q: x = q.popleft() # ... q.append(y) -- The saddest aspect of life right now is that science gathers knowledge faster than society gathers wisdom. -- Isaac Asimov Roel Schroeven -- http://mail.python.org/mailman/listinfo/python-list
extract multiple ranges from a list
Hi guys, One of my many project involves working with YUV-files, where I need to reduce the vertical resolution with a factor of two, i.e. remove every other scan line. Today I'm using two for-loops in the fashion shown below y = [] for i in range(0, width*height, width*2): for j in range(0,width): y.append(Y[i+j]) This approach doesn't feel very pythonic but I can't come up with a better idea to do it. I've tried list comprehension and map together with lambda but I can't get a flattened list of every other scan-line... CIF = 352x288 items for luminance and the aim is to have the list below: y = [0:352 704:1056 ... ] //Fredrik -- http://mail.python.org/mailman/listinfo/python-list
Re: Regarding coding style
On 2008-03-08, [EMAIL PROTECTED] [EMAIL PROTECTED] wrote: The function name also doesn't explain anything. How was the stuff got? Was it paid for, or stolen, or picked up on consignment, or what? Compare the above line with: x = get_stuff(store) # Steal stuff from the store. or x = get_stuff(store) # Pickup the stuff from the store for disposal. # The amount paid by the store is stored in global variable pay_received # and the name of the employee authorizing the pickup is stored in the # global authorized_by. Shouldn't get_stuff's comment be with its definition? Probably, but better that comment shouldn't be anywhere. get_stuff() should be 1) renamed, as you state below. 2) written such that it's obvious from reading the source code that the amount paid is stored in the global variable pay_received and that the name of the employee authorizing the pickup is stored in the global authorized by. But, it's not really fare picking on an example like that... And just rename the function to something more meaningful, like purchase_goods(store), or whatever. But even if you were right that the comment was unnecessary, you have missed my point that even single sentences can be grammatically bogus and the writer could learn a lot from Strunk and White or equivalent. That's true. I don't know how many times I've seen a single sentence comment that was just plain vague and ambiguous. And most of the time they're just plain wrong as well because the code had been changed but nobody changed the comment (possibly because they couldn't understand what the comment was trying to say). -- Grant Edwards grante Yow! I was giving HAIR at CUTS to th' SAUCER PEOPLE visi.com... I'm CLEAN!! -- http://mail.python.org/mailman/listinfo/python-list
Re: Can't get items out of a set?
Cruxic wrote: people = set( [Person(1, 'Joe'), Person(2, 'Sue')] ) ... p = people.get_equivalent(2) #method doesn't exist as far as I know print p.name #prints Sue def get_equivalent(test, container): for p in container: if p == test: return p hth, Alan Isaac #example (note change in __eq__ to match your case; fix if nec) class Person: def __init__(self, id, name): self.id = id self.name = name def __hash__(self): return self.id def __eq__(self, other): return self.id == other people = set( [Person(1, 'Joe'), Person(2, 'Sue')] ) get_equivalent(2,people) -- http://mail.python.org/mailman/listinfo/python-list
Re: extract multiple ranges from a list
On Mar 8, 3:28 pm, [EMAIL PROTECTED] wrote: Hi guys, One of my many project involves working with YUV-files, where I need to reduce the vertical resolution with a factor of two, i.e. remove every other scan line. Today I'm using two for-loops in the fashion shown below y = [] for i in range(0, width*height, width*2): for j in range(0,width): y.append(Y[i+j]) There's nothing really wrong with your code. Maybe it's a little nicer written like this: y = [] for i in range(0, height, 2): y.extend(Y[i * width + j] for j in range(width)) -- Paul Hankin -- http://mail.python.org/mailman/listinfo/python-list
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Re: List as FIFO in for loop
malkarouri wrote: Hi everyone, I have an algorithm in which I need to use a loop over a queue on which I push values within the loop, sort of: while not(q.empty()): x = q.get() #process x to get zero or more y's #for each y: q.put(y) The easiest thing I can do is use a list as a queue and a normal for loop: q = [a, b, c] for x in q: #process x to get zero or more y's q.append(y) It makes me feel kind of uncomfortable, though it seems to work. The question is: is it guaranteed to work, or does Python expect that you wouldn't change the list in the loop? I have used exactly the same approach. I think it's a clean (even elegant) solution. I'd be surprised if it ceased to work in some future implementation of Python, but I don't know if that's absolutely guaranteed. Duncan -- http://mail.python.org/mailman/listinfo/python-list
Re: List as FIFO in for loop
On Mar 8, 3:20 pm, Roel Schroeven [EMAIL PROTECTED] wrote: malkarouri schreef: Hi everyone, I have an algorithm in which I need to use a loop over a queue on which I push values within the loop, sort of: while not(q.empty()): x = q.get() #process x to get zero or more y's #for each y: q.put(y) The easiest thing I can do is use a list as a queue and a normal for loop: q = [a, b, c] for x in q: #process x to get zero or more y's q.append(y) It makes me feel kind of uncomfortable, though it seems to work. The question is: is it guaranteed to work, or does Python expect that you wouldn't change the list in the loop? Changing a loop while iterating over it is to be avoided, if possible. In any case, a deque is more efficient for this kind of use. I'd use it like this: from collections import deque q = deque([a, b, c]) while q: x = q.popleft() # ... q.append(y) -- The saddest aspect of life right now is that science gathers knowledge faster than society gathers wisdom. -- Isaac Asimov Roel Schroeven Thanks for your response. My same feeling, avoid loop variable, but no explicit reason. Thanks for reminding me of the deque, which I never used before. Alas, in terms of efficiency - which I need - I don't really need to pop the value on the list/deque. This additional step takes time enough to slow the loop a lot. So its not ideal here. Still, why avoid changing loop variable? Does python treat looping over a list differently from looping over an iterator, where it doesn't know if the iterator future changes while loop running? Regards, Muhammad Alkarouri -- http://mail.python.org/mailman/listinfo/python-list
Re: List as FIFO in for loop
On Mar 8, 3:52 pm, duncan smith [EMAIL PROTECTED] wrote: malkarouri wrote: Hi everyone, I have an algorithm in which I need to use a loop over a queue on which I push values within the loop, sort of: while not(q.empty()): x = q.get() #process x to get zero or more y's #for each y: q.put(y) The easiest thing I can do is use a list as a queue and a normal for loop: q = [a, b, c] for x in q: #process x to get zero or more y's q.append(y) It makes me feel kind of uncomfortable, though it seems to work. The question is: is it guaranteed to work, or does Python expect that you wouldn't change the list in the loop? I have used exactly the same approach. I think it's a clean (even elegant) solution. I'd be surprised if it ceased to work in some future implementation of Python, but I don't know if that's absolutely guaranteed. Duncan Thanks Duncan, I think I will go ahead and use it. Though the Python tutorial says otherwise in section 4.2: It is not safe to modify the sequence being iterated over in the loop (this can only happen for mutable sequence types, such as lists). If you need to modify the list you are iterating over (for example, to duplicate selected items) you must iterate over a copy.. More explicitly, in 7.3 of the Python Reference Manual: Warning: There is a subtlety when the sequence is being modified by the loop (this can only occur for mutable sequences, i.e. lists). An internal counter is used to keep track of which item is used next, and this is incremented on each iteration. When this counter has reached the length of the sequence the loop terminates. This means that if the suite deletes the current (or a previous) item from the sequence, the next item will be skipped (since it gets the index of the current item which has already been treated). Likewise, if the suite inserts an item in the sequence before the current item, the current item will be treated again the next time through the loop. This can be interpreted as don't play with the past. However, the part When this counter has reached the length of the sequence the loop terminates. is interpretable as either the starting sequence length or the running sequence length. Testing: In [89]: x=range(4) In [90]: for i in x: : print i : x.append(i+4) : if i=8:break : : 0 1 2 3 4 5 6 7 8 So it is the running sequence length. But I am still not sure if that is guaranteed. Regards, Muhammad Alkarouri -- http://mail.python.org/mailman/listinfo/python-list
Re: Can't get items out of a set?
On Mar 7, 11:20 am, Raymond Hettinger [EMAIL PROTECTED] wrote: [Cruxic] Is it possible to get an object out of a set() given another object that has the same hash code and equality (__hash__() and __eq__() return the same)? Yes, but it requires an indirect approach.http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/499299 Raymond That's a clever work around. Thanks, Raymond. Clearly you had a need for this. Do you feel it's a common need that should be submitted as a Python feature request? To me it seems like such a simple thing that would increase the general utility of the set class. I suppose I could start another thread like feature request: New method for set - get_equivalent. -- http://mail.python.org/mailman/listinfo/python-list
Re: Can't get items out of a set?
On Mar 8, 7:32 am, Alan Isaac [EMAIL PROTECTED] wrote: Cruxic wrote: people = set( [Person(1, 'Joe'), Person(2, 'Sue')] ) ... p = people.get_equivalent(2) #method doesn't exist as far as I know print p.name #prints Sue def get_equivalent(test, container): for p in container: if p == test: return p hth, Alan Isaac #example (note change in __eq__ to match your case; fix if nec) class Person: def __init__(self, id, name): self.id = id self.name = name def __hash__(self): return self.id def __eq__(self, other): return self.id == other people = set( [Person(1, 'Joe'), Person(2, 'Sue')] ) get_equivalent(2,people) That works fine for small data sets but my goal is to avoid a linear search, instead leveraging the O(1) lookup time for a hash based set. -- http://mail.python.org/mailman/listinfo/python-list
Re: parralel downloads
For your problem you have to use threads. You can have more information here. http://artfulcode.nfshost.com/files/multi-threading-in-python.html On Sat, Mar 8, 2008 at 1:11 PM, John Deas [EMAIL PROTECTED] wrote: Hi, I would like to write a python script that will download a list of files (mainly mp3s) from Internet. For this, I thought to use urllib, with urlopen(myUrl).read() and then writing the resulting string to a file my problem is that I would like to download several files at the time. As I have not much experience in programming, could you point me the easier ways to do this in python ? Thanks, JD -- http://mail.python.org/mailman/listinfo/python-list -- http://mail.python.org/mailman/listinfo/python-list
Re: extract multiple ranges from a list
[EMAIL PROTECTED] wrote: One of my many project involves working with YUV-files, where I need to reduce the vertical resolution with a factor of two, i.e. remove every other scan line. Today I'm using two for-loops in the fashion shown below y = [] for i in range(0, width*height, width*2): for j in range(0,width): y.append(Y[i+j]) This approach doesn't feel very pythonic but I can't come up with a better idea to do it. I've tried list comprehension and map together with lambda but I can't get a flattened list of every other scan-line... CIF = 352x288 items for luminance and the aim is to have the list below: y = [0:352 704:1056 ... ] width = 3; height = 5 Y = range(width*height) y = [] for i in range(0, width*height, 2*width): ... y.extend(Y[i:i+width]) ... y [0, 1, 2, 6, 7, 8, 12, 13, 14] Probably more efficient, but needs numpy: import numpy width = 3 height = 5 Y = range(width*height) a = numpy.array(Y).reshape(height, width) a array([[ 0, 1, 2], [ 3, 4, 5], [ 6, 7, 8], [ 9, 10, 11], [12, 13, 14]]) b = a[::2] b array([[ 0, 1, 2], [ 6, 7, 8], [12, 13, 14]]) list(b.reshape(len(b)*width)) [0, 1, 2, 6, 7, 8, 12, 13, 14] Peter -- http://mail.python.org/mailman/listinfo/python-list
Re: float / rounding question
On Mar 7, 11:23 pm, Steven D'Aprano [EMAIL PROTECTED] cybersource.com.au wrote: On Fri, 07 Mar 2008 23:12:27 +0100, Piet van Oostrum wrote: Sorry to come in so late in this discussion. Although it is correct to say that many real numbers that have an exact decimal representation cannot be exactly represented in binary, that is no excuse to print 53.6 as 53.601. This is just lousy printing and the fact that this kind of question comes up every week shows that it is confusing to many people. Good. That's a feature, not a bug. Even so, it's not clear that Python's current behaviour couldn't be improved. I have a mild dislike of the lack of consistency in the following, which arises from Python arbitrarily stripping trailing zeros from the result returned by the C library functions: 10.1 10.1 10.2 10.199 10.3 10.301 10.4 10.4 Piet van Oostrum's suggestion gives one nice way of dealing with this inconsistency. Unfortunately it doesn't look easy to implement this in practice: the main difficulty seems to be that to ensure float(repr(x))==x round-tripping you'd need to write routines to take control of both str - float and float - str conversions, not forgetting that those routines have to be reasonably fast, and work correctly on various non IEEE 754 platforms as well as the usual ones. This means adding, maintaining and testing hundreds of lines of complicated code, where right now a few C library calls suffice. Mark -- http://mail.python.org/mailman/listinfo/python-list
Re: List as FIFO in for loop
Still, why avoid changing loop variable? Does python treat looping over a list differently from looping over an iterator, where it doesn't know if the iterator future changes while loop running? Take a look at Objects/listobject.c:listiterobject. It contains an it_index, which is the index into the list of the current iterator position. So if you delete items with indices smaller than the iterator index, the iterator index won't change, causing the iterator to skip over elements, e.g. L=range(10) for i in L: print i del L[0] Appending to lists will cause the new elements to be iterated over later. Whether that's desirable or not depends on the application. E.g. the following loop never terminates L=range(10: for i in L: L.append(i) Notice that the language specification *deliberately* does not distinguish between deletion of earlier and later items, but makes modification of the sequence undefined behavior to allow alternative implementations. E.g. an implementation that would crash, erase your hard disk, or set your house in flames if you confront it with your code still might be a conforming Python implementation. Regards, Martin -- http://mail.python.org/mailman/listinfo/python-list
Re: parralel downloads
poof65 wrote: For your problem you have to use threads. Not at all true. Thread provide one way to solve this, but another is the select function. For this simple case, select() may (or may not) be easier to write. Pseudo-code would look something like this: openSockets = list of sockets one per download file: while openSockets: readySockets = select(openSockets ...) # Identifies sockets with data to be read for each s in readSockets: read from s and do whatever with the data if s is at EOF: close and remove s from openSockets That's it. Far easier than threads. Gary Herron You can have more information here. http://artfulcode.nfshost.com/files/multi-threading-in-python.html On Sat, Mar 8, 2008 at 1:11 PM, John Deas [EMAIL PROTECTED] wrote: Hi, I would like to write a python script that will download a list of files (mainly mp3s) from Internet. For this, I thought to use urllib, with urlopen(myUrl).read() and then writing the resulting string to a file my problem is that I would like to download several files at the time. As I have not much experience in programming, could you point me the easier ways to do this in python ? Thanks, JD -- http://mail.python.org/mailman/listinfo/python-list -- http://mail.python.org/mailman/listinfo/python-list
SQL problem in python
class db:
def __init__(self): #constructor
conn = sqlite3.connect(:memory:)
conn.isolation_level = None
self.cursor = conn.cursor()
self.cursor.execute(CREATE TABLE database (album,filepath))
def add_entry(self, eone , etwo): #Add entry to database
self.cursor.execute(INSERT INTO database (album,filepath)
VALUES (?,?), ( eone , etwo ) )
return 1 #TODO: exception handler
def get_mediadb(self, print_db = False):
self.cursor.execute('SELECT * FROM database')
if (print_db == True):
print self.cursor.fetchall()
def get_value( self, column ):
self.cursor.execute( SELECT (?) FROM database, column )
for n in self.cursor:
print n
def destructor(self):
self.cursor.close()
if __name__ == __main__:
f = db()
f.add_entry( Pinkk Floyd, fdgf )
f.add_entry( Pink, fdgf )
# f.get_mediadb(print_db=True)
f.get_value(('filepath',))
f.destructor()
When i run it the get_value() returns 'filepath' instead of the
columns. But if i dont use any variable and make the expression static
all goes on as its supposed to. What am i doing wrong?
PS: Dont mind the bad code
--
http://mail.python.org/mailman/listinfo/python-list
Re: Converting a string to the most probable type
On Mar 8, 12:19 am, rockingred [EMAIL PROTECTED] wrote: Dates can be a pain. I wrote my own date program, simply because there are so many different ways to write a date: Mar 8, 2008 March 8th, 08 03/08/08 03-08-2008 And so on and so forth. The tricky bit is how to tell the difference between Day, Month and Year. I wrote a program to check the format used for a date. I assumed that any 4 digits together in a single group were the year. Then I had a list of Months, with the first 3 characters of each and compared that to the field being checked, if found, then that was the month. Then I assumed any number greater than 12 was a day. If I couldn't match those criteria I assumed Month Day Year (the standard at the company I worked for). If humans are sometimes confused about this, how could a computer reliably tells the correct date? I don't think it's possible (to _reliably_ convert string to date), unless you've got an agreed convention on how to input the date. -- http://mail.python.org/mailman/listinfo/python-list
Re: float / rounding question
On Mar 8, 11:34 am, Mark Dickinson [EMAIL PROTECTED] wrote: following, which arises from Python arbitrarily stripping trailing zeros from the result returned by the C library functions: Correction: on closer examination it's not Python doing the stripping of trailing zeros; it's the C library. Mark -- http://mail.python.org/mailman/listinfo/python-list
Re: SQL problem in python
On Sat, 2008-03-08 at 08:57 -0800, aiwarrior wrote: def get_value( self, column ): self.cursor.execute( SELECT (?) FROM database, column ) for n in self.cursor: print n When i run it the get_value() returns 'filepath' instead of the columns. But if i dont use any variable and make the expression static all goes on as its supposed to. What am i doing wrong? Using parameter binding wherever possible is a Good Idea, but parameter binding can only be used to provide values. It can not be used to provide syntax elements, table names, or column names. Basically, only pieces that don't influence the query plan can be provided by parameters. To build a select query with a variable column name, you'll have to resort to some kind of string building mechanism: def get_value( self, column ): self.cursor.execute( SELECT %s FROM database % column ) for n in self.cursor: print n HTH, -- Carsten Haese http://informixdb.sourceforge.net -- http://mail.python.org/mailman/listinfo/python-list
Re: SQL problem in python
aiwarrior wrote: When i run it the get_value() returns 'filepath' instead of the columns. But if i dont use any variable and make the expression static all goes on as its supposed to. What am i doing wrong? self.cursor.execute( SELECT (?) FROM database, column ) In this case you have to use Python's string interpolation, or the column will be interpreted as a const value. The following should work: self.cursor.execute( SELECT %s FROM database % column) If you must sanitize the column name you can prepend something like if column not in allowed_names: raise ValueError Peter -- http://mail.python.org/mailman/listinfo/python-list
Re: Converting a string to the most probable type
On Mar 8, 8:34 am, Steven D'Aprano [EMAIL PROTECTED] cybersource.com.au wrote: On Fri, 07 Mar 2008 16:13:04 -0800, Paul Rubin wrote: Pierre Quentel [EMAIL PROTECTED] writes: I would like to know if there is a module that converts a string to a value of the most probable type Python 2.4.4 (#1, Oct 23 2006, 13:58:00) import this The Zen of Python, by Tim Peters ... In the face of ambiguity, refuse the temptation to guess. Good advice, but one which really only applies to libraries. At the application level, sometimes (but not always, or even most times!) guessing is the right thing to do. Guessing should only be done when it have to be done. Users should input data in an unambiguous way (such as using 4 digit years and textual month name, this is the most preferred solution, as flexibility is retained but ambiguity is ruled out) or be forced to use a certain convention or be aware of how to properly input the date. Guessing should be done at the minimum. Personally, when I'm working with spreadsheet applications (in MS Office or OpenOffice) I always input dates in an unambiguous way using 4-digit year and textual month name (usually the 3-letter abbrevs for quicker inputting), then I can confidently rely the spreadsheet to convert it to its internal format correctly. The general parsers like the OP wanted are easy to create if dates aren't involved. E.g. spreadsheet applications don't insist on different syntax for strings, dates and numbers. You can use syntax to force one or the other, but by default the application will auto-detect what you want according to relatively simple, predictable and intuitive rules: * if the string looks like a date, it's a date; * if it looks like a number, it's a number; * otherwise it's a string. The worse thing that can happen is when we input a date in a format we know but the application can't parse and it consider it as a string instead. This kind of thing can sometimes easily pass our nose. I remembered I once formatted a column in Excel to write date with certain style, but when I tried to input the date with the same style, Excel can't recognize it, making the whole column rendered as useless string and requiring me to reinput the dates again. Given the user-base of the application, the consequences of a wrong guess, and the ease of fixing it, guessing is the right thing to do. Auto-completion is another good example of guessing in the face of ambiguity. It's not guessing that is bad, but what you do with the guess. -- Steven -- http://mail.python.org/mailman/listinfo/python-list
Re: SQL problem in python
Thanks a lot. In the Python documentation, the sqlite module documentation doesn't mention that special rule. I really thought that every variable to be included in a query had to use that special method. Again thanks a lot -- http://mail.python.org/mailman/listinfo/python-list
Re: Intelligent Date Time parsing
On Mar 7, 9:23 pm, [EMAIL PROTECTED] wrote: I figured I might as well share the code I ended up using, in case anyone else wants an easy way to get strings to, for instance, SQL- storable datetimes. [EMAIL PROTECTED]:~$ cat test.py #!/usr/bin/python from datetime import datetime import subprocess def parsedate( date ): p = subprocess.Popen(['date','+%s.%N',--date=%s % date],stdout=subprocess.PIPE) out = float(p.stdout.read()) return %s % datetime.fromtimestamp(out) [EMAIL PROTECTED]:~$ python -i test.py parsedate(today) '2008-03-07 21:20:31.870489' parsedate(tomorrow) '2008-03-08 21:20:40.516243' parsedate(next monday) '2008-03-10 00:00:00' parsedate(10pm last week) '2008-02-29 22:00:00' parsedate(last tuesday) '2008-03-04 00:00:00' I am a GNU newbie. (I know C o.) Can you point me to a place to find the source for 'date'? -- http://mail.python.org/mailman/listinfo/python-list
Re: tcp
On Sun, 02 Mar 2008 23:05:27 -0500, Roy Smith wrote:
In article
[EMAIL PROTECTED],
Gabriel Genellina [EMAIL PROTECTED] wrote:
On 2 mar, 17:21, [EMAIL PROTECTED] wrote:
This worked:
import socket
from time import time
for i in range( 20 ):
HOST = ''
PORT = 80 #
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.bind((HOST, PORT))
print( 'listen' )
s.listen(1)
conn, addr = s.accept()
print( 'connected', addr )
print( conn.recv( 4096 ) ) #
conn.send( bytes('htmlbodytest %f/body/
html'%time(),'ascii') )
conn.close() #
s.close()
... and connect with a browser: http://localhost/if it's internet
exploder.
Note that there is no need (nor is desirable) to close and rebind the
listening socket for each connection.
I'd say, nor is desirable, is an understatement. On most systems, an
attempt to re-bind to a given port number soon after it was unbound will
fail (unless you utter magic ioctl incantations). This will manifest
itself in the s.bind() call raising an exception on the *second* pass
through the loop.
I believe the incantation may be setsockopt(), not ioctl(), but if
there's an ioctl() way of doing it, i'd be interested in seeing it.
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Re: Regarding coding style
On Mar 8, 9:31 am, Grant Edwards [EMAIL PROTECTED] wrote: On 2008-03-08, [EMAIL PROTECTED] [EMAIL PROTECTED] wrote: The function name also doesn't explain anything. How was the stuff got? Was it paid for, or stolen, or picked up on consignment, or what? Compare the above line with: x = get_stuff(store) # Steal stuff from the store. or x = get_stuff(store) # Pickup the stuff from the store for disposal. # The amount paid by the store is stored in global variable pay_received # and the name of the employee authorizing the pickup is stored in the # global authorized_by. Shouldn't get_stuff's comment be with its definition? Probably, but better that comment shouldn't be anywhere. get_stuff() should be 1) renamed, as you state below. 2) written such that it's obvious from reading the source code that the amount paid is stored in the global variable pay_received and that the name of the employee authorizing the pickup is stored in the global authorized by. But, it's not really fare picking on an example like that... And just rename the function to something more meaningful, like purchase_goods(store), or whatever. But even if you were right that the comment was unnecessary, you have missed my point that even single sentences can be grammatically bogus and the writer could learn a lot from Strunk and White or equivalent. That's true. I don't know how many times I've seen a single sentence comment that was just plain vague and ambiguous. And most of the time they're just plain wrong as well because the code had been changed but nobody changed the comment (possibly because they couldn't understand what the comment was trying to say). There are bad comments and bad variable names. fcrg= dothingthatgoesplace( qkjwvm ). # that thing I talked about # in last Tuesday's code for searching qkjwvm and returning its attribute. Does one side of this hold that there are no -good- comments? -- http://mail.python.org/mailman/listinfo/python-list
Re: Regarding coding style
Personally I preferred a code that has chosen good names but have little or no comments compared to codes that makes bad names and have twenty pages of comments to read and understand what it's about. Personally, I think comments should be made as short and as concise as possible and codes should try to be self-understandable if the comments aren't accessible. -- http://mail.python.org/mailman/listinfo/python-list
Help xxx.py Program Recognition problem
Hi... I was using Python 2.4 and installed 2.5...I copied all my .py files from the Python24\ root directory to the Python25\ root directory...when I try to run them by double clicking I get: X.py is not a valid Win32 application... Also, the files do not appear to be associated with python...? I can run them from IDLE...but that is it... How do I fix this...? Thanks.. Dave -- http://mail.python.org/mailman/listinfo/python-list
Re: What is a class?
On Mar 7, 6:16 am, Steven D'Aprano [EMAIL PROTECTED] cybersource.com.au wrote: On Thu, 06 Mar 2008 08:40:47 -0800, castironpi wrote: you could say exec( open( 'modA.py' ).read() ) == import modA Yes, you could say that, but you'd be wrong. Please test your code before making such claims in the future. Aye aye. -1 response not phrased in the form of a question. Is it correct that exec( open( 'modA.py' ).read() ) -and- from modA import * create effectively same results, such as in the remaning program not checking __module__ attributes? Is there a slight modification of both sides that does cover a non- trivial volume of programs, such as maybe, exec( open( 'modA.py' ).read(), locals= dict( __module__= 'modA' ) ) - and- from modA import *, or something? I notice that from toimp import * f() exec( open( 'toimp.py' ).read() ) f() generate the same output so far. -- http://mail.python.org/mailman/listinfo/python-list
Re: Intelligent Date Time parsing
I am a GNU newbie. (I know C o.) Can you point me to a place to find the source for 'date'? It's part of the GNU Coreutils: http://ftp.gnu.org/gnu/coreutils/ Within the file, you're likely interested in lib/getdate.* It helps if you have a working knowledge of Yacc. -tkc -- http://mail.python.org/mailman/listinfo/python-list
Re: Difference between 'function' and 'method'
On Mar 7, 1:34 pm, [EMAIL PROTECTED] wrote: On Mar 7, 6:44 am, Sion Arrowsmith [EMAIL PROTECTED] wrote: Gabriel Genellina [EMAIL PROTECTED] wrote: En Thu, 06 Mar 2008 23:46:43 -0200, [EMAIL PROTECTED] escribi�: [ ... ] You may look at the SimpleXMLRPCServer class and see how it implements introspection. It's rather easy (and doesn't require metaclasses nor decorators nor any other fancy stuff; I think it works the same since Python 2.1). Apparently you're doing a similar thing, but using pickles instead of xmlrpc. It's not that difficult to graft pickles into SimpleXMLRPCServer -- I've done it, and if you're trying to sling large data structures over the connection it's a massive performance win (even with sgmlop in place to speed up XML parsing). her nu becomeþ se bera eadward ofdun hlæddre heafdes bæce bump bump bump Yeah, but I'd be grafting a non-blocking RPC sequence too. -Instantiate- attributes of ISS upon instantiation. class C: d= D c= C() assert isinstance( c.d, D ) assert c.d is c.d Which ones? Two options: instantiate all attributes, or ones with a certain property, such as name or superclass. class C: inst_d= D #actually gets bound to 'd', optionally class C: d= inst( D ) I think what I'm looking for is an attribute wrapper. class C: @inst d= D But the closest the syntax goes is: class C: class d( D ): pass (which takes us back to one of Steven's posts some days ago.) ( def f(x=None):/class C:/x= X/return C. ) and the d= inst( D ) solution.) You either need to assign something to assign something to its name, class C: d= X or declare it, but that only allows def and class statements (correct?). class C: attr d: D is ideal. -- http://mail.python.org/mailman/listinfo/python-list
Re: multiplication of lists of strings
On Mar 5, 2:16 am, Bruno Desthuilliers bruno. [EMAIL PROTECTED] wrote: [EMAIL PROTECTED] a écrit : (snip) That reminds me: Is there a generic 'relation' pattern/recipie, such as finding a computer that's paired with multiple users, each of who are paired with multiple computers, without maintaining dual- associativity? Yes : use a relational database. No performance hit. Can I write an ad hoc relational class structure? -- http://mail.python.org/mailman/listinfo/python-list
Re: Converting a string to the most probable type
def convert(x):
if '.' in x:
try: return float(x)
except ValueError: return x
else:
try: return int(x)
except: return x
convert('123')
123
convert('123.99')
123.98
convert('hello')
Hi,
That's fine for people who write floats with a . ; but others learn
to enter them with ,
For the same float, the French write the literal 123.456.789,99 when
others write 123,456,789.99 ; for us, today is 8/3/2008 (or
08/03/2008) where for others it's 3/8/2008 or perhaps 2008/3/8
Popular spreadsheets know how to guess literals ; if the guess is
not correct users can usually specify the pattern to use. My question
was just to know if something similar had already been developed in
Python ; I understand that the answer is no
Thanks,
Pierre
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Re: multiplication of lists of strings
On Mar 8, 12:04 pm, [EMAIL PROTECTED] wrote: On Mar 5, 2:16 am, Bruno Desthuilliers bruno. [EMAIL PROTECTED] wrote: [EMAIL PROTECTED] a écrit : (snip) That reminds me: Is there a generic 'relation' pattern/recipie, such as finding a computer that's paired with multiple users, each of who are paired with multiple computers, without maintaining dual- associativity? Yes : use a relational database. No performance hit. Can I write an ad hoc relational class structure? What do you think of this solution? http://jtauber.com/blog/2005/11/10/relational_python:_basic_class_for_relations/ http://www.google.com/search?hl=enq=python+relational+class+-database -- http://mail.python.org/mailman/listinfo/python-list
Re: List as FIFO in for loop
On Mar 8, 9:43 am, malkarouri [EMAIL PROTECTED] wrote: Hi everyone, I have an algorithm in which I need to use a loop over a queue on which I push values within the loop, sort of: while not(q.empty()): x = q.get() #process x to get zero or more y's #for each y: q.put(y) The easiest thing I can do is use a list as a queue and a normal for loop: q = [a, b, c] for x in q: #process x to get zero or more y's q.append(y) It makes me feel kind of uncomfortable, though it seems to work. The question is: is it guaranteed to work, or does Python expect that you wouldn't change the list in the loop? Regards, Muhammad Alkarouri I think it's a bad practice to get into. Did you intend to do the process step again over the added variables? If not I would set a new variable, based on your awful naming convention, let's call it z. Then use z.append(y) within the for loop and after you are out of your for loop, q.append(z). -- http://mail.python.org/mailman/listinfo/python-list
del class with recursive list
Hello! Will someone have time to tell me why this code don't work as I expect? And what should I do to make the del n delete all the lower nodes? Thanks! class Node: def __init__(self): self.childs=[] def appendNode(self, n): self.childs.append(n) def __del__(self): print 'del', id(self) n = Node() for i in range(5): n.appendNode(Node()) for nodes in n.childs: nodes.appendNode(Node()) del n print 'end' gives this: del 10965280 del 10965440 del 10965640 del 10965400 del 10965600 del 10965360 del 10965560 del 10965320 del 10965520 end del 10965480 del 10965680 -- http://mail.python.org/mailman/listinfo/python-list
Re: SQL problem in python
On Sat, 2008-03-08 at 10:11 -0800, Dennis Lee Bieber wrote: On Sat, 8 Mar 2008 09:28:23 -0800 (PST), aiwarrior [EMAIL PROTECTED] declaimed the following in comp.lang.python: Thanks a lot. In the Python documentation, the sqlite module documentation doesn't mention that special rule. I really thought that every variable to be included in a query had to use that special method. It's not sqlite specific -- it is common to all of the db-api compatible adapters. The explanation for why you were getting 'filename' (or whatever the field was is: parameter substitution ensures that the parameter value is properly quoted and escaped to be safe for use as a value. It's called parameter binding, not parameter substitution. Parameter binding ensures that the value is passed to the database safely. That need not necessarily be a quoting-and-escaping exercise. Depending on the API module, it may use a mechanism that transmits the query string and the parameters to the database engine separately. Also note that SQL standard doesn't even allow parameters in the projection clause of a select statement. SQLite is just more relaxed about the standard than for example Informix: import informixdb conn = informixdb.connect(stores_demo) cur = conn.cursor() cur.execute(select ? from customer, (customer_num,) ) Traceback (most recent call last): File stdin, line 1, in module _informixdb.ProgrammingError: SQLCODE -201 in PREPARE: 42000: Syntax error or access violation -- Carsten Haese http://informixdb.sourceforge.net -- http://mail.python.org/mailman/listinfo/python-list
Re: del class with recursive list
duccio wrote: Will someone have time to tell me why this code don't work as I expect? And what should I do to make the del n delete all the lower nodes? Thanks! class Node: def __init__(self): self.childs=[] def appendNode(self, n): self.childs.append(n) def __del__(self): print 'del', id(self) n = Node() for i in range(5): n.appendNode(Node()) for nodes in n.childs: nodes.appendNode(Node()) # you forgot a reference to a child node and its child: del nodes del n print 'end' gives this: del 10965280 del 10965440 del 10965640 del 10965400 del 10965600 del 10965360 del 10965560 del 10965320 del 10965520 end del 10965480 del 10965680 Peter -- http://mail.python.org/mailman/listinfo/python-list
Image Libraries
I have been using PIL for generating images, however it does not easily support operations with transparency etc. I tried to install aggdraw but it wouldn't compile. Ideally I'd like something open source so I can adapt it, hopefully mostly written in python rather than C. Is there any other decent image libraries for python? -- http://mail.python.org/mailman/listinfo/python-list
Re: Can't get items out of a set?
Is it possible to get an object out of a set() given another object
that has the same hash code and equality (__hash__() and __eq__()
return the same)?
Yes, but it requires an indirect
approach.http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/499299
Raymond
That's a clever work around. Thanks, Raymond. Clearly you had a need
for this. Do you feel it's a common need that should be submitted as
a Python feature request? To me it seems like such a simple thing
that would increase the general utility of the set class. I suppose I
could start another thread like feature request: New method for set -
get_equivalent.
Glad you liked the recipe. :-) FWIW, it is not specific to sets. The
recipe works with any container including dictionaries and lists. The
approach is easily extended to any situation with equality testing.
For example, it can be used with list.remove(x) to find the identity
of the removed object.
Long ago, I rejected adding get_equivalent() to the set API. The
existing API has a near zero learning curve and it would be nice to
keep it that way.
For most use cases, the obvious, explicit approach is better. Just
make a dictionary where the value is the canonical representative of
the equivalence class:
d = {1:1, 2:2, 3:3}
d[2.0]
2
The intern() builtin uses this approach:
interned = {}
def intern(s):
if s in interned:
return interned[s]
interned[s] = s
return s
Raymond
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Re: Converting a string to the most probable type
On Mar 8, 12:05 pm, Pierre Quentel [EMAIL PROTECTED] wrote:
def convert(x):
if '.' in x:
try: return float(x)
except ValueError: return x
else:
try: return int(x)
except: return x
convert('123')
123
convert('123.99')
123.98
convert('hello')
Hi,
That's fine for people who write floats with a . ; but others learn
to enter them with ,
For the same float, the French write the literal 123.456.789,99 when
others write 123,456,789.99 ; for us, today is 8/3/2008 (or
08/03/2008) where for others it's 3/8/2008 or perhaps 2008/3/8
Popular spreadsheets know how to guess literals ; if the guess is
not correct users can usually specify the pattern to use. My question
was just to know if something similar had already been developed in
Python ; I understand that the answer is no
Thanks,
Pierre
In particular, you can retain access to the user/interface, and always
just query when probabilities aren't 100%. In general, retain access
to a higher power, such as offering a hook ( def butdonotguess( raw,
guesses ):). If you're making the decision, and a case-by-case is too
expensive, then you've made a policy, and someone gets shaft 'cause
policy. You can throw an exception that's guaranteed to be handled
or exits. '121212' isn't as bad as '121110'! If you want to find out
who and when writes dates like that, apply to PR. Obviously a person
knew at one point what the string was; how much is left?
P.S. def welltheydidthatthistime( raw, guesses ):.
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Intra-Package References
Does your python module have to exist in the path in order for intra- package references to work? Regards, Kenneth Miller -- http://mail.python.org/mailman/listinfo/python-list
Re: Python CGI Webpage with an Image
Is the cgi script in the same directory? The user's browser looks for the jpg relative to the URL it used to get the page, which in the case of the CGI script is the path to the script, not the path to the html file. No the CGI script is in a different folder, I could move everything to the same folder I guess. If server logs are hard to get or read, try my runcgi.py script: http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/550822 Thanks, I will try this. Rod -- http://mail.python.org/mailman/listinfo/python-list
Re: Regarding coding style
On 2008-03-08, [EMAIL PROTECTED] [EMAIL PROTECTED] wrote: Does one side of this hold that there are no -good- comments? I wouldn't say there are _no_ good comments, but I would say that 90+% of the comments I've seen in my lifetime were bad. Most of them were bad to the extent that anybody new to the code would be best served by deleting them before trying to understand what was going on. I do think that a comment at the beginning of a function/module that describes its general purpose can be a good thing. A comment explaining a particularly opaque algorithm can be useful as well. rant What I really can't stand are the pointy-haired comment blocks at the beginnings of C/C++ functions that do things like tell you the name and return type of the function and list the names and types of the parameters. Gee, thanks. I never could have figured that out from looking at the source code itself. IMO, comments explaining what the parameters are used for usually indicates that the parameter names were poorly chosen. I'm also a bit baffled by people who put a comment at the top of every file that tells you what the filename is. I sometimes wonder how/where these files were created. All of the OSes I've ever used had a feature called a filesystem which kept track of info like the names of files. It must be a bitch-and-a-half to work on an computer that doesn't keep track of filenames and makes the user do it. When was the last time you thought to yourself: Gee, I wonder what's the the name of that file over there? I guess I'd better open the file and look at the comment at the top to see what the filename is? /rant -- Grant Edwards grante Yow! .. does your DRESSING at ROOM have enough ASPARAGUS? visi.com -- http://mail.python.org/mailman/listinfo/python-list
identifying and parsing string in text file
I have a large file that has many lines like this, element tag=300a,0014 vr=CS vm=1 len=4 name=DoseReferenceStructureTypeSITE/element I would like to identify the line by the tag (300a,0014) and then grab the name (DoseReferenceStructureType) and value (SITE). I would like to create a file that would have the structure, DoseReferenceStructureType = Site ... ... Also, there is a possibility that there are multiple lines with the same tag, but different values. These all need to be recorded. So far, I have a little bit of code to look at everything that is available, for line in open(str(sys.argv[1])): i_line = line.split() if i_line: if i_line[0] == element: a = i_line[1] b = i_line[5] print %s | %s %(a, b) but do not see a clever way of doing what I would like. Any help or guidance would be appreciated. Bryan -- http://mail.python.org/mailman/listinfo/python-list
Re: SQL problem in python
Maybe you should try SQLObject :-)
from sqlobject import *
from sqlobject.sqlbuilder import Select
#from sqlobject.sqlbuilder import *
from datetime import datetime
# === sqlite ==
#connection = connectionForURI('sqlite:///dev/shm/ourdata.db')
connection = connectionForURI('sqlite:/:memory:')
sqlhub.processConnection = connection
class MyTable(SQLObject):
album= StringCol(length=20, default=None)
filepath = StringCol(length=50, default=None)
#MyTable.dropTable(ifExists=True)
#MyTable._connection.debug = True # you can switch debuging ON, so you
can see SQL commands generated by SQLObject
MyTable.createTable(ifNotExists=True)
MyTable(album =Pinkk Floyd, filepath= qwst )
MyTable(album =Pinkk, filepath= gbfbd )
MyTable(album =Floyd, filepath= fdgf )
q = MyTable.select()
for row in q:
print row.album, row.filepath
for row in MyTable.select(MyTable.q.album == Pinkk Floyd):
print row.album, row.filepath
HTH
Petr Jakes
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Re: Regarding coding style
On Mar 8, 1:31 pm, Grant Edwards [EMAIL PROTECTED] wrote: On 2008-03-08, [EMAIL PROTECTED] [EMAIL PROTECTED] wrote: Does one side of this hold that there are no -good- comments? I wouldn't say there are _no_ good comments, but I would say that 90+% of the comments I've seen in my lifetime were bad. Limit your comments, in other words. emLIM-IT/em. comment explaining a particularly opaque algorithm can be useful as well. But can't the name do that? wink at the beginnings of C/C++ functions that do things like tell you the name and return type of the function and list the names and types of the parameters. Gee, thanks. I never could have figured that out from looking at the source code itself. IMO, Sometimes void*s are guaranteed to be HTHREADs. I'm also a bit baffled by people who put a comment at the top of every file that tells you what the filename is. I sometimes wonder how/where these files were created. All of the OSes I've ever used had a feature called a filesystem which kept track of info like the names of files. It must be a bitch-and-a-half to work on an computer that doesn't keep track of filenames and makes the user do it. When was the last time you thought to yourself: Gee, I wonder what's the the name of that file over there? I guess I'd better open the file and look at the comment at the top to see what the filename is? What file did you open? To Lie: Personally I preferred a code that has chosen good names but have little or no comments compared to codes that makes bad names and have Personally I don't. Show me a good one. Until you do, it's not that I won't like it, it's that I can't. You know, in linguistics, there's what's called 'code switching', which is switching between two languages you know midstream. People can understand 'hear' a language but not speak it. If you speak it, leaves open. If comments aren't the 'short version', then patience is the problem. There's not one word for lots and lots of things. Examples on backorder. Good comments are better than bad names. Good names are better than bad comments. And enter multi-word identifiers. wink -- http://mail.python.org/mailman/listinfo/python-list
Re: identifying and parsing string in text file
Hey Brian, It seems the text you are trying to parse is similar to XML/HTML. So I'd use BeautifulSoup[1] if I were you :) here's a sample code for your scraping case: from BeautifulSoup import BeautifulSoup python # assume the s variable has your text s = whatever xml or html here # turn it into a tasty parsable soup :) soup = BeautifulSoup(s) # for every element tag in the soup for el in soup.findAll(element): # print out its tag name attribute plus its inner value! print el[tag], el[name], el.string /python that's it! [1] http://www.crummy.com/software/BeautifulSoup/ On 8 mar, 14:49, [EMAIL PROTECTED] [EMAIL PROTECTED] wrote: I have a large file that has many lines like this, element tag=300a,0014 vr=CS vm=1 len=4 name=DoseReferenceStructureTypeSITE/element I would like to identify the line by the tag (300a,0014) and then grab the name (DoseReferenceStructureType) and value (SITE). I would like to create a file that would have the structure, DoseReferenceStructureType = Site ... ... Also, there is a possibility that there are multiple lines with the same tag, but different values. These all need to be recorded. So far, I have a little bit of code to look at everything that is available, for line in open(str(sys.argv[1])): i_line = line.split() if i_line: if i_line[0] == element: a = i_line[1] b = i_line[5] print %s | %s %(a, b) but do not see a clever way of doing what I would like. Any help or guidance would be appreciated. Bryan -- http://mail.python.org/mailman/listinfo/python-list
Re: identifying and parsing string in text file
[EMAIL PROTECTED] wrote:
I have a large file that has many lines like this,
element tag=300a,0014 vr=CS vm=1 len=4
name=DoseReferenceStructureTypeSITE/element
I would like to identify the line by the tag (300a,0014) and then grab
the name (DoseReferenceStructureType) and value (SITE).
I would like to create a file that would have the structure,
DoseReferenceStructureType = Site
...
...
You should try with Regular Expressions or if it is something like xml there
is for sure a library you can you to parse it ...
anyway you can try something simpler like this:
elem_dic=dict()
for line in open(str(sys.argv[1])):
line_splitted=line.split()
for item in line_splitted:
item_splitted=item.split(=)
if len(item_splitted)1:
elem_dic[item_splitted[0]]=item_splitted[1]
... then you have to retrieve from the dict the items you need, for example,
with the line you posted you obtain these items splitted:
['element']
['tag', '300a,0014']
['vr', 'CS']
['vm', '1']
['len', '4']
['name', 'DoseReferenceStructureTypeSITE/element']
and elem_dic will contain the last five, with the keys
'tag','vr','vm','len','name' and teh values 300a,0014 etc etc
i.e. this:
{'vr': 'CS', 'tag': '300a,0014', 'vm': '1', 'len': '4', 'name':
'DoseReferenceStructureTypeSITE/element'}
--
Age is not a particularly interesting subject. Anyone can get old. All
you have to do is live long enough.
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SV: Regarding coding style
What I really can't stand are the pointy-haired comment blocks at the beginnings of C/C++ functions that do things like tell you the name and return type of the function and list the names and types of the parameters. Gee, thanks. I never could have figured that out from looking at the source code itself. Coming from C++/Java camp i can't help noticing that in most cases, when i'm using a class written by somebody else, i don't want to see his/her code. I only want to know WHAT the function does (is intended to be doing, at least). I don't want to look at the source code (in some cases i can't even see the code because it's compiled). I only care that when i execute SomeType obj = SomeType(); obj.aggregate(); the object gets aggregated. How it's done will be up to the author. I'm just a user of the product. Now, i'm getting the signal that it's done in a different way in Python. Please elaborate. I'm very new to snakeology. -- Regards Konrad Viltersten sleep- a substitute for coffee for the poor ambition - lack of sense to be lazy -- http://mail.python.org/mailman/listinfo/python-list
Adjust a canvas as the window is resized
Do i need to set a callback to a canvas in order to listen to the root window being resized in order to make it adjust its contents? If so, how? If not, how do i make the canvas draw a line from one corner to an other? from Tkinter import * class Demo(Frame): def __init__(self, master = None): Frame.__init__(self, master) self.grid() self.doLayout() master.geometry(800x600) def doLayout(self): canvas = Canvas(self, bd = 3, bg = #93F) canvas.grid(column = 0, row = 0) canvas.create_line(0, 0, 100, 200, fill = #FFF) def callback(self): print callback from canvas root = Tk() demo = Demo(root) root.mainloop() -- Regards Konrad Viltersten sleep- a substitute for coffee for the poor ambition - lack of sense to be lazy -- http://mail.python.org/mailman/listinfo/python-list
Re: Regarding coding style
On Mar 8, 1:31 pm, Grant Edwards [EMAIL PROTECTED] wrote: On 2008-03-08, [EMAIL PROTECTED] [EMAIL PROTECTED] wrote: Does one side of this hold that there are no -good- comments? I wouldn't say there are _no_ good comments, but I would say that 90+% of the comments I've seen in my lifetime were bad. Limit your comments, in other words. emLIM-IT/em. comment explaining a particularly opaque algorithm can be useful as well. But can't the name do that? wink at the beginnings of C/C++ functions that do things like tell you the name and return type of the function and list the names and types of the parameters. Gee, thanks. I never could have figured that out from looking at the source code itself. IMO, Sometimes void*s are guaranteed to be HTHREADs. I'm also a bit baffled by people who put a comment at the top of every file that tells you what the filename is. I sometimes wonder how/where these files were created. All of the OSes I've ever used had a feature called a filesystem which kept track of info like the names of files. It must be a bitch-and-a-half to work on an computer that doesn't keep track of filenames and makes the user do it. When was the last time you thought to yourself: Gee, I wonder what's the the name of that file over there? I guess I'd better open the file and look at the comment at the top to see what the filename is? What file did you open? To Lie: Personally I preferred a code that has chosen good names but have little or no comments compared to codes that makes bad names and have Personally I don't. Show me a good one. Until you do, it's not that I won't like it, it's that I can't. You know, in linguistics, there's what's called 'code switching', which is switching between two languages you know midstream. People can understand 'hear' a language but not speak it. If you speak it, leaves open. If comments aren't the 'short version', then patience is the problem. There's not one word for lots and lots of things. Examples on backorder. Good comments are better than bad names. Good names are better than bad comments. And enter multi-word identifiers. wink -- http://mail.python.org/mailman/listinfo/python-list
Re: for-else
The idea of the if-else is: . depending on some condition either do this or do something else, . don't do them both. yes = the loop completed. 'else' isn't rechecking a piece of the loop, it's checking the loop. Does it test successfully--- not the loop condition, the loop? What is 'if a loop'? Make sense, I hold it does. (Holding is good-- something I can drop and give to someone else.) If 'else' gets hit, I didn't do the loop. -- http://mail.python.org/mailman/listinfo/python-list
Re: Can't get items out of a set?
something something equivalence class.
The intern() builtin uses this approach:
interned = {}
def intern(s):
if s in interned:
return interned[s]
interned[s] = s
return s
If you've seen it before, and have the old one, return the old one.
Do I have this straight?
--
http://mail.python.org/mailman/listinfo/python-list
Re: List as FIFO in for loop
Notice that the language specification *deliberately* does not distinguish between deletion of earlier and later items, but makes modification of the sequence undefined behavior to allow alternative implementations. E.g. an implementation that would crash, erase your hard disk, or set your house in flames if you confront it with your code still might be a conforming Python implementation. Actually, PEP 4122 makes this a SetHouseInFlames error. Do you want to include this one? Just use _toaddafter= type( container )(). P.S. Equivalence class light, on the rocks. -- http://mail.python.org/mailman/listinfo/python-list
Re: distutils - Is is possible to install without the .py extensions
Jari Aalto wrote: * Fri 2008-03-07 Robert Kern [EMAIL PROTECTED] gmane.comp.python.general * Message-Id: [EMAIL PROTECTED] setup(name='program', ... scripts = ['program,py'], ) that the the result is: /usr/bin/program instead of: /usr/bin/program.py The easiest and best way is to just rename the file in your source tree to program and be done with it. Is there any other way? This is the source package that I would like to keep intact and just patch the setup.py Not really, no. Why is it so important to only patch the setup.py file and not any others? It has to do with generating a diff against the original package. If the file is moved: mv file.py file prior setup.py run (which, according to answers, would have a change to scripts = ['program']), the problem is the generated diff against original sources: + would flag removal of 'file.py' + inclusion of 'file' The ideal would be if setup.py could do all the destination install postwork. The generated patch would be clean and only contain changes in setup.py. But I understand, if distutils does not support stripping the extensions during install. It just cacuses exra work for utility packagers. What build system are you using that doesn't let you execute cp file.py file before running the setup.py? -- Robert Kern I have come to believe that the whole world is an enigma, a harmless enigma that is made terrible by our own mad attempt to interpret it as though it had an underlying truth. -- Umberto Eco -- http://mail.python.org/mailman/listinfo/python-list
Re: for-else
egbert [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] | However the loop-else really works more like this: | . try to do the loop; | . if it starts but is interrupted by a break, | . then do something else as well. This is NOT how loop-else works for Python. If you want to do something special on breaks, put the break-only code before the break. while loop_condition: loop statements if break_condition: break-only statements break more loop stuff | So they are completely different beasts, and if you try to use | or explain the one according to the rules of the other one, | you put a serious strain on your synapses. I did not mean to broke your brain. | The explanation that the if-else and the loop-else | follow the same pattern, runs more or less like this: | . all conditions to run the loop to its completion were met, | . which means that the loop-condition is not met (any more), | . which means that we must do something else. | For me that is orwellian logic: success is failure. I gave a clear and coherent explanation of how while derives from if, and correspondingly, how while-else derives from if-else, to help those who want to read and write Python code. Building on the pseudo-snippet above, one can write while loop_condition: loop statements if break_condition: break-only statements break more loop stuff else: completion-only statements Python allows one to have both break-only and completion-only sections together in one compound statement and *without* having to fiddle with a special flag variable. I am sorry if you cannot appreciate such elegance and can only spit on it as 'orwellian'. If the sense of else were reversed, one would have to write the clumbsier complete = True # though false at this point while loop_condition: loop statements if break_condition: complete = False break more loop stuff else: break-only statements if complete: completion-only statements Terry Jan Reedy -- http://mail.python.org/mailman/listinfo/python-list
Re: Regarding coding style
On Mar 8, 1:31 pm, Grant Edwards [EMAIL PROTECTED] wrote: hilarious rant snipped LOL. Thanks for the laughs. I share your frustration. -- http://mail.python.org/mailman/listinfo/python-list
Re: Regarding coding style
On Mar 8, 2:27 pm, [EMAIL PROTECTED] wrote: Good comments are better than bad names. Good names are better than bad comments. If you're taking the time to write good comments, why not just fix the bad names? The compiler/interpreter can never, ever catch bad comments. -- http://mail.python.org/mailman/listinfo/python-list
Re: SV: Regarding coding style
On 2008-03-08, K Viltersten [EMAIL PROTECTED] wrote: What I really can't stand are the pointy-haired comment blocks at the beginnings of C/C++ functions that do things like tell you the name and return type of the function and list the names and types of the parameters. Gee, thanks. I never could have figured that out from looking at the source code itself. Coming from C++/Java camp i can't help noticing that in most cases, when i'm using a class written by somebody else, i don't want to see his/her code. I only want to know WHAT the function does (is intended to be doing, at least). If you can't/don't look at the source file, then comments aren't going to help (except in the case of something like docstrings in Python). I don't want to look at the source code (in some cases i can't even see the code because it's compiled). I only care that when i execute SomeType obj = SomeType(); obj.aggregate(); the object gets aggregated. How it's done will be up to the author. I'm just a user of the product. If you don't look at the source file, then I guess the question of whether comments are good, bad, or indifferent is irrelevent to you. Now, i'm getting the signal that it's done in a different way in Python. I'm not sure how you concluded that from this thread. I very rarely look at the source files for the standard library. I usually just look at the library reference document. The only times I look at the source code are the rare occasion that the function doesn't seem to be working correctly or when I can't understand what the reference docs are saying. The cases where I suspect the former generally turn out to be the latter. Comments in source code are for people maintaining the code, not for people using a standard library API (again, except for docstrings). -- Grant Edwards grante Yow! YOU PICKED KARL at MALDEN'S NOSE!! visi.com -- http://mail.python.org/mailman/listinfo/python-list
Re: identifying and parsing string in text file
On Mar 8, 2:02 pm, Nemesis [EMAIL PROTECTED] wrote: [EMAIL PROTECTED] wrote: I have a large file that has many lines like this, element tag=300a,0014 vr=CS vm=1 len=4 name=DoseReferenceStructureTypeSITE/element I would like to identify the line by the tag (300a,0014) and then grab the name (DoseReferenceStructureType) and value (SITE). You should try with Regular Expressions or if it is something like xml there is for sure a library you can you to parse it ... snip When it comes to parsing HTML or XML of uncontrolled origin, regular expressions are an iffy proposition. You'd be amazed what kind of junk shows up inside an XML (or worse, HTML) tag. Pyparsing includes a builtin method for constructing tag matching parsing patterns, which you can then use to scan through the XML or HTML source: from pyparsing import makeXMLTags, withAttribute, SkipTo testdata = blah element tag=300a,0014 vr=CS vm=1 len=4 name=DoseReferenceStructureTypeSITE/element element tag=300Z,0019 vr=CS vm=1 len=4 name=DoseReferenceStructureTypeSITEXXX/element element tag=300a,0014 vr=CS vm=1 len=4 name=DoseReferenceStructureTypeSITE2/element blahblah elementStart,elementEnd = makeXMLTags(element) elementStart.setParseAction(withAttribute(tag=300a,0014)) search = elementStart + SkipTo(elementEnd)(body) for t in search.searchString(testdata): print t.name print t.body Prints: DoseReferenceStructureType SITE DoseReferenceStructureType SITE2 In this case, the parse action withAttribute filters element tag matches, accepting *only* those with the attribute tag and the value 300a,0014. The pattern search adds on the body of the element/ element tag, and gives it the name body so it is easily accessed after parsing is completed. -- Paul (More about pyparsing at http://pyparsing.wikispaces.com.) -- http://mail.python.org/mailman/listinfo/python-list
off topic: 2 videos on source control and open source development
I just wanted to send out links to 2 informative videos regarding open source and change control systems. The first is Linus Torvalds on git and how it contrasts with subversion and other approaches (where he says some nice things about Mercurial, btw). http://www.youtube.com/watch?v=4XpnKHJAok8 This one is about managing the community dynamics in the subversion project. http://video.google.nl/videoplay?docid=-4216011961522818645 It only made me a little uncomfortable at certain moments :). Good viewing. -- Aaron Watters === http://www.xfeedme.com/nucular/pydistro.py/go?FREETEXT=mileage -- http://mail.python.org/mailman/listinfo/python-list
Parse specific text in email body to CSV file
I have been searching all over for a solution to this. I am new to Python, so I'm a little lost. Any pointers would be a great help. I have a couple hundred emails that contain data I would like to incorporate into a database or CSV file. I want to search the email for specific text. The emails basically look like this: random text _important text:_15648 random text random text random text random text random text random text random text _important text:_15493 random text random text random text random text _important text:_11674 random text random text random text ===Date: Wednesday March 5, 2008 name1: 15name5: 14 name2: 18name6: 105 name3: 64name7: 2 name4: 24name8: 13 I want information like name1: 15 to be placed into the CSV with the name name1 and the value 15. The same goes for the date and _important text:_15493. I would like to use this CSV or database to plot a graph with the data. Thanks! -- http://mail.python.org/mailman/listinfo/python-list
Re: List as FIFO in for loop
On Mar 8, 4:44 pm, Martin v. Löwis [EMAIL PROTECTED] wrote: ... Notice that the language specification *deliberately* does not distinguish between deletion of earlier and later items, but makes modification of the sequence undefined behavior to allow alternative implementations. E.g. an implementation that would crash, erase your hard disk, or set your house in flames if you confront it with your code still might be a conforming Python implementation. Really appreciated, Martin. It was exactly the *deliberately* part I am interested in. Settles it for me. Thanks, Muhammad Alkarouri -- http://mail.python.org/mailman/listinfo/python-list
Re: extract multiple ranges from a list
On 8 Mar, 17:32, Peter Otten [EMAIL PROTECTED] wrote: [EMAIL PROTECTED] wrote: One of my many project involves working with YUV-files, where I need to reduce the vertical resolution with a factor of two, i.e. remove every other scan line. Today I'm using two for-loops in the fashion shown below y = [] for i in range(0, width*height, width*2): for j in range(0,width): y.append(Y[i+j]) This approach doesn't feel very pythonic but I can't come up with a better idea to do it. I've tried list comprehension and map together with lambda but I can't get a flattened list of every other scan-line... CIF = 352x288 items for luminance and the aim is to have the list below: y = [0:352 704:1056 ... ] width = 3; height = 5 Y = range(width*height) y = [] for i in range(0, width*height, 2*width): ... y.extend(Y[i:i+width]) ... y [0, 1, 2, 6, 7, 8, 12, 13, 14] Probably more efficient, but needs numpy: import numpy width = 3 height = 5 Y = range(width*height) a = numpy.array(Y).reshape(height, width) a array([[ 0, 1, 2], [ 3, 4, 5], [ 6, 7, 8], [ 9, 10, 11], [12, 13, 14]]) b = a[::2] b array([[ 0, 1, 2], [ 6, 7, 8], [12, 13, 14]]) list(b.reshape(len(b)*width)) [0, 1, 2, 6, 7, 8, 12, 13, 14] Peter Thanx guys! -- http://mail.python.org/mailman/listinfo/python-list
Fwd: [PyQt] Popen + poll pid
Hi, I sent the question below to the wrong list. I was wondering if someone here could help? Kevin Sent from my iPhone Begin forwarded message: From: Kevin [EMAIL PROTECTED] Date: March 8, 2008 11:53:39 AM PST To: [EMAIL PROTECTED] [EMAIL PROTECTED] Subject: [PyQt] Popen + poll pid I've been trying to use the poll and pid attributes of popen to determine if mplayer is finished playing an audio track. I've tried using popen, popen2, popen3, etc but it tells me that there is no poll or PID module. Could anyone help me with a proper method to determine if a process is running or ended so that I can move to the next track and start another iteration? Either that or does someone know how to change audio cd tracks in mplayer slave mode? ;) Kevin Sent from my iPhone ___ PyQt mailing list[EMAIL PROTECTED] http://www.riverbankcomputing.com/mailman/listinfo/pyqt -- http://mail.python.org/mailman/listinfo/python-list
Re: List as FIFO in for loop
On Mar 8, 6:24 pm, rockingred [EMAIL PROTECTED] wrote: I think it's a bad practice to get into. Did you intend to do the process step again over the added variables? If not I would set a new variable, based on your awful naming convention, let's call it z. Then use z.append(y) within the for loop and after you are out of your for loop, q.append(z). Thanks, rockingred, for the advice. I hope that you didn't assume that I was a newbie, even if my question looks so. What I was trying to do is write some Python code which I need to optimize as much as possible. I am using Cython (Pyrex) and would probably end up rewriting my whole module in C at one point, but it is really hard to beat Python data structures at their home turf. So meanwhile, I am making use of dubious optimizations - on my own responsibility. There have been a lot of these along the years - like using variables leaking from list expressions (not anymore). Think of it as a goto. Yes, I intend to do the process step again over the added variables. The suggested deque is probably the best, though I need the speed here. What are the variable naming you would suggest, for a throwaway - probably anonymized for the same of publishing on the web - code? Cheers, Muhammad Alkarouri -- http://mail.python.org/mailman/listinfo/python-list
Re: List as FIFO in for loop
On Mar 8, 9:43 am, malkarouri [EMAIL PROTECTED] wrote: Hi everyone, I have an algorithm in which I need to use a loop over a queue on which I push values within the loop, sort of: while not(q.empty()): x = q.get() #process x to get zero or more y's #for each y: q.put(y) Why not just do it like that? With a few changes it'll work fine: while q: x = q.pop(0) for y in process(x): q.append(y) And consider collections.deque for q instead of a list, though it shouldn't make much of a difference if the queue remains small. Carl Banks -- http://mail.python.org/mailman/listinfo/python-list
SV: SV: Regarding coding style
If you can't/don't look at the source file, then comments aren't going to help (except in the case of something like docstrings in Python). I strongly disagree. Now, perhaps we're talking about different things, here? Usually, in the header file (C++), there won't be any source code, except for method declarations. A common example: /** Projects an object from 3D to 2D using the method of Alexander The Great. \param 3D structure to be projected \returns 2D projection */ public Proj2D get2Dfrom3D(Proj3D param); The above is, to me, very clear and consistent. Not to mention, easily handled with e.g. Doxygen to create a readable documentation. I don't see how this is dislikeable. Please explain. Perhaps the above IS what you ment by docstrings? For Java, one has the JavaDocs, a great tool, provided one will comment each method and variable used. Now, i'm getting the signal that it's done in a different way in Python. I'm not sure how you concluded that from this thread. The below, more or less. :) What I really can't stand are the pointy-haired comment blocks at the beginnings of C/C++ functions that do things like tell you the name and return type of the function and list the names and types of the parameters. Please note that i DO NOT argue against one way or another. I simply expressed surprise since i've been tought otherwise earlier and, maybe, there's a larger picture than what i've seen this far. As stated before, snakeology is a very new area to me. Yet. ;) -- Regards Konrad Viltersten sleep- a substitute for coffee for the poor ambition - lack of sense to be lazy -- http://mail.python.org/mailman/listinfo/python-list
Re: SV: Quit-command not quiting
En Fri, 07 Mar 2008 13:56:45 -0200, K Viltersten [EMAIL PROTECTED] escribi�: The window itself vanishes if i click the cross in the upper-right corner but pressing the quit-button only makes it pressed. Then, the program freezes. How did you run it? From inside IDLE? IDLE itself is written using Tk, and I think that your mainloop interferes with the one inside it. If you run your program from the command line it should work fine. I press F5 while in the editor window. Is there a way to run the program without going to the console window? Perhaps i'm just making things unneccesarily complicated and Python IS supposed to be run from console window? No, use IDLE if you prefer, or any other editor/IDE. But in your case there is an unfortunate coupling between IDLE and your script. Fix: change the quit method as suggested in this thread: http://groups.google.com/group/comp.lang.python/browse_thread/thread/92bee52a3e2a325e/ def quit(self): self.master.destroy() This is OK if used on the top level widget on the application (your Demo class, for instance). A more general solution: def quit(self): parent = self while parent.winfo_class() != 'Tk': if parent.master is None: break; parent = parent.master else: parent.destroy() (from https://sourceforge.net/tracker/index.php?func=detailaid=661324group_id=9579atid=109579 ) This appears to work fine. But the loop, as written, could exit without calling destroy() on anything; perhaps some other people knowing better how Tkinter and Tk work could improve it or confirm it's fine as it is. -- Gabriel Genellina -- http://mail.python.org/mailman/listinfo/python-list
Arbitrary precision integer arithmetic: ceiling?
I need to apply the ceiling function to arbitrary sized (long) integers. However, division automatically returns the type of its operands, so that, for example: math.ceil(7/4) returns 1. I can use float, as in: math.ceil(7/float(4)), except that for very large integers float causes an unacceptable loss of precision. What is the best way of finding a ceiling of a quotient of arbitrary sized integers? Thanks, Alasdair -- http://mail.python.org/mailman/listinfo/python-list
Re: Arbitrary precision integer arithmetic: ceiling?
Alasdair [EMAIL PROTECTED] writes: What is the best way of finding a ceiling of a quotient of arbitrary sized integers? ceiling(a/b) = (a+b-1)//b -- http://mail.python.org/mailman/listinfo/python-list
Re: Arbitrary precision integer arithmetic: ceiling?
Alasdair wrote: I need to apply the ceiling function to arbitrary sized (long) integers. However, division automatically returns the type of its operands, so that, for example: math.ceil(7/4) returns 1. I can use float, as in: math.ceil(7/float(4)), except that for very large integers float causes an unacceptable loss of precision. What is the best way of finding a ceiling of a quotient of arbitrary sized integers? Use divmod() to get the quotient and the remainder at the same time. Add 1 to the quotient if and only the remainder is greater than 0. In [11]: def qceil(x, y): : Find the ceiling of a quotient x/y. : : This is especially useful for very large Python long integers. : : q, r = divmod(x, y) : if r 0: : q += 1 : return q : In [13]: qceil(7, 4) Out[13]: 2 In [14]: qceil(8, 4) Out[14]: 2 In [15]: qceil(9, 4) Out[15]: 3 In [16]: qceil(103, 10) Out[16]: 11L -- Robert Kern I have come to believe that the whole world is an enigma, a harmless enigma that is made terrible by our own mad attempt to interpret it as though it had an underlying truth. -- Umberto Eco -- http://mail.python.org/mailman/listinfo/python-list
Re: SV: SV: Regarding coding style
On 2008-03-08, K Viltersten [EMAIL PROTECTED] wrote: If you can't/don't look at the source file, then comments aren't going to help (except in the case of something like docstrings in Python). I strongly disagree. Now, perhaps we're talking about different things, here? Usually, in the header file (C++), there won't be any source code, except for method declarations. A common example: /** Projects an object from 3D to 2D using the method of Alexander The Great. \param 3D structure to be projected \returns 2D projection */ public Proj2D get2Dfrom3D(Proj3D param); The above is, to me, very clear and consistent. Not to mention, easily handled with e.g. Doxygen to create a readable documentation. I don't see how this is dislikeable. Please explain. Perhaps the above IS what you ment by docstrings? For Java, one has the JavaDocs, a great tool, provided one will comment each method and variable used. The problem is that tools like Doxygen and JavaDocs generate warnings and errors and things if everything isn't documented completely. So you end up with a lot of silly boilerplate. I see this kind of nonsense a lot: /** * Get the width of a box * * @param box the box * @returns its width */ extern int box_get_width(box box); You are right that is it often useful to document what to pass to a method and what to expect back and that if this is done well in many cases it isn't necessary to see the implementation. But in many other cases it's obvious, and in other cases it's obvious if you just look at the source which you've got. What's needed is just a bit of common sense and pragmatism: APIs need more documentation if the source of the implementation isn't being released with them, and some APIs just need more documentation than others anyway. Python docstrings, like most things in Python, demonstrate this kind of common sense: you write what you want in them and as far as I can tell nothing complains if you don't write them at all. The lack of fascism is the big innovation. It sounds simple but it makes a huge difference: it's much easier to find (and keep up to date) the real documentation if it's not hidden in a forest of bogus documentation. -- http://mail.python.org/mailman/listinfo/python-list
Re: float / rounding question
Mark Dickinson schreef: On Mar 7, 11:23 pm, Steven D'Aprano [EMAIL PROTECTED] cybersource.com.au wrote: On Fri, 07 Mar 2008 23:12:27 +0100, Piet van Oostrum wrote: Sorry to come in so late in this discussion. Although it is correct to say that many real numbers that have an exact decimal representation cannot be exactly represented in binary, that is no excuse to print 53.6 as 53.601. This is just lousy printing and the fact that this kind of question comes up every week shows that it is confusing to many people. Good. That's a feature, not a bug. Even so, it's not clear that Python's current behaviour couldn't be improved. I have a mild dislike of the lack of consistency in the following, which arises from Python arbitrarily stripping trailing zeros from the result returned by the C library functions: 10.1 10.1 10.2 10.199 10.3 10.301 10.4 10.4 Actually I don't see what all the fuss is about. If you want a nicely rounded number, use print or str() or the % operator. *Only* when you use repr() or when the interactive interpreter uses it to print the value of the expression, you get something that doesn't look as nice. -- The saddest aspect of life right now is that science gathers knowledge faster than society gathers wisdom. -- Isaac Asimov Roel Schroeven -- http://mail.python.org/mailman/listinfo/python-list
Green's Function
Hi All, I am new to Python and trying to solve the Hamiltonian of a linear chair of atoms using greens function. Does anyone know any pre-existing library functions and literature that could be helpful? Thanks EOF - Looking for last minute shopping deals? Find them fast with Yahoo! Search.-- http://mail.python.org/mailman/listinfo/python-list
Re: List as FIFO in for loop
On Mar 8, 10:42 pm, Carl Banks [EMAIL PROTECTED] wrote: On Mar 8, 9:43 am, malkarouri [EMAIL PROTECTED] wrote: Hi everyone, I have an algorithm in which I need to use a loop over a queue on which I push values within the loop, sort of: while not(q.empty()): x = q.get() #process x to get zero or more y's #for each y: q.put(y) Why not just do it like that? With a few changes it'll work fine: while q: x = q.pop(0) for y in process(x): q.append(y) Or (almost) equivalently... while q: x = q.pop(0) q.extend(process(x)) -- Paul Hankin -- http://mail.python.org/mailman/listinfo/python-list
Re: What is a class?
On Sat, 08 Mar 2008 09:52:41 -0800, castironpi wrote:
On Mar 7, 6:16 am, Steven D'Aprano [EMAIL PROTECTED]
cybersource.com.au wrote:
On Thu, 06 Mar 2008 08:40:47 -0800, castironpi wrote:
you
could say exec( open( 'modA.py' ).read() ) == import modA
Yes, you could say that, but you'd be wrong. Please test your code
before making such claims in the future.
Aye aye. -1 response not phrased in the form of a question.
All the words in that sentence are English, but as a whole it makes no
sense.
Is it correct that exec( open( 'modA.py' ).read() ) -and- from modA
import * create effectively same results,
You're getting closer now. (By the way, exec is a statement, so you don't
need brackets around its arguments.)
exec open('modA.py').read()
gives *almost* the same results as
from modA import *
The differences I can think of:
(1) The exec version doesn't cache the results, so if you execute the
line repeatedly you will execute the same code over and over again,
possibly causing unexpected side-effects. import caches the results, and
so will be faster.
(2) The import version may read from modA.pyc, modA.pyo or modA.so even
if there is a modA.py file. The exec version can't import from anything
but modA.py.
(3) The exec version as written always puts the results in the global
scope, even if you execute it inside a function. (In the future, from
modA import * will be forbidden inside functions, but at the moment it
is still legal.)
(4) The exec version doesn't search sys.path for modA; import does.
(5) The exec version can't read modules inside a zip file; import can.
There may be other differences I haven't thought of.
such as in the remaning
program not checking __module__ attributes?
Again, I don't understand what you are saying.
Is there a slight modification of both sides that does cover a non-
trivial volume of programs, such as maybe, exec( open( 'modA.py'
).read(), locals= dict( __module__= 'modA' ) ) - and- from modA import
*, or something?
*Slight* modification, no.
I'm sure that with sufficient effort, you could add caching, search
sys.path, and look inside zip files. Those three things wouldn't be
horribly difficult, but it wouldn't be a one-liner -- off the top of my
head, I'd guess fifty to a hundred lines of code to re-invent those
particular wheels correctly.
However, recreating the rest of the import mechanism would be terribly
complicated. I'm not really sure it could be done. For example, how would
you deal with modules written in C from within Python? You'd need access
to Python internals that, as far as I know, aren't available.
--
Steven
--
http://mail.python.org/mailman/listinfo/python-list
Re: Regarding coding style
On Sat, 08 Mar 2008 19:31:47 +, Grant Edwards wrote: I'm also a bit baffled by people who put a comment at the top of every file that tells you what the filename is. [snip rant] You've never printed out a source file on pieces of dead tree to read on the train on the way home, or in bed or the bath? Yes, some editors will print a header or footer showing the file name, but not all will, or are configured to do so. -- Steven -- http://mail.python.org/mailman/listinfo/python-list
Re: SV: Regarding coding style
On Sat, 08 Mar 2008 21:21:48 +0100, K Viltersten wrote: Coming from C++/Java camp i can't help noticing that in most cases, when i'm using a class written by somebody else, i don't want to see his/her code. I only want to know WHAT the function does (is intended to be doing, at least). I don't want to look at the source code (in some cases i can't even see the code because it's compiled). I only care that when i execute SomeType obj = SomeType(); obj.aggregate(); the object gets aggregated. How it's done will be up to the author. I'm just a user of the product. Now, i'm getting the signal that it's done in a different way in Python. Please elaborate. I'm very new to snakeology. I think even Grant would agree that when you call help(make_widget), you should see something like: make_widget(styleID, material) - widget or raise ValueError on failure styleID: numeric ID or string name of the widget style material: WidgetMaterial instance or None to use default rather than: See source code for details. *wink* -- Steven -- http://mail.python.org/mailman/listinfo/python-list
