ANN: Twisted version 2.0
http://twistedmatrix.com/ TASMANIA (DP) -- Found on the Internet on 2005-03-22 by an anonymous programmer, Twisted 2.0 was obtained by local authorities and kept isolated for public safety and further study. On 2005-03-25, however, nano-probes were released from the package's surface and propagated the software to the public. Version 2.0 is said to have originated from ancient underground ruins somewhere in Australia, but their existence has not yet been verified. Christopher Armstrong, enslaved release archaeologist, was only able to say Aieeya! Release?? What release? I just found this here tablet under some sand. Ia! Project lead Glyph Lefkowitz was not available for comment, as he has fled the planet in fear of the repercussions of the software's new release. Record-keeper Mary Gardiner said It will be interesting to see if the Twisted Sumo distribution collapses into a singularity. I guess there's a potential that Earth will be destroyed. As of this release, radix's soul, which has been included in Twisted since version 0.8.0, has been split off from the main project and given back to him to maintain in a separate sub-project. Twisted 2.0 is a major upgrade, changing many things not only in the code but also in the structure of the project. As of 2.0, Twisted was split up into many sub-projects which you can read about in the Twisted Split FAQ[1]. 2.0 also marks the first release including the migration to the Zope Interface framework as opposed to Twisted's own built-in interface/adapter system. Another FAQ was made available[2] for those curious about the change. Many, tons, and lots of other changes have been made in this release. The NEWS[3] file contains a high-level overview of most of these changes. Changes in now-split subprojects are available on their individual project pages[4]. Tarballs are currently available at the twistedmatrix.com site, and packages for win32, Debian, and other OSes are currently on the way. 1: http://twistedmatrix.com/projects/core/documentation/upgrades/2.0/split.html 2: http://twistedmatrix.com/projects/core/documentation/upgrades/2.0/components.html 3: http://twistedmatrix.com/projects/core/NEWS.txt 4: http://twistedmatrix.com/projects/ WHAT IS TWISTED? Twisted is an event-based framework for internet applications which works on Python 2.2.X and 2.3.X. The following are the (important) modules included with Twisted: - twisted.application A Service system that allows you to organize your application in hierarchies with well-defined startup and dependency semantics, - twisted.cred A general credentials and authentication system that facilitates pluggable authentication backends, - twisted.enterprise Asynchronous database access, compatible with any Python DBAPI2.0 modules, - twisted.internet Low-level asynchronous networking APIs that allow you to define your own protocols that run over certain transports, - twisted.manhole A tool for remote debugging of your services which gives you a Python interactive interpreter, - twisted.protocols Basic protocol implementations and helpers for your own protocol implementations, - twisted.python A large set of utilities for Python tricks, reflection, text processing, and anything else, - twisted.spread A secure, fast remote object system, - twisted.trial A unit testing framework that integrates well with Twisted-based code. Twisted supports integration of the Tk, GTK+, GTK+ 2, Qt, Mac OS X, or wxPython event loop with its main event loop. The Win32 event loop is also supported. For more information, visit http://www.twistedmatrix.com, or join the list at http://twistedmatrix.com/cgi-bin/mailman/listinfo/twisted-python There are many official Twisted subprojects, including clients and servers for web, mail, DNS, and more. You can find out more about these projects at http://twistedmatrix.com/projects/ -- Twisted | Christopher Armstrong: International Man of Twistery Radix|-- http://radix.twistedmatrix.com | Release Manager, Twisted Project \\\V/// |-- http://twistedmatrix.com |o O|| Founding Member, Hobart Hacking Society wvw-+-- http://hackingsociety.org/chapters/hash -- http://mail.python.org/mailman/listinfo/python-announce-list Support the Python Software Foundation: http://www.python.org/psf/donations.html
ANN: PythonDoc 2.1 beta 3 (march 25, 2005)
PythonDoc is a documentation tool for Python, inspired by JavaDoc. Like JavaDoc, PythonDoc scans your Python code for doc comments, and generates API documentation in XML and HTML formats. Python- Doc supports basic JavaDoc tags like @param and @return, and adds a few Python-specific tags. You can use PythonDoc comments to describe module-level variables and constants, functions, classes, methods, and attributes. PythonDoc comes with a standard HTML generator, but you can plug in your own output handlers, or use XSLT or other tools to process the PythonDoc XML format. PythonDoc 2.1b3 parses docstrings and adds them to the XML model. It also includes some minor bug fixes. See the README file for details. Downloads: http://effbot.org/downloads#pythondoc http://effbot.org/downloads#elementtree Documentation: http://effbot.org/zone/pythondoc.htm enjoy /F -- http://mail.python.org/mailman/listinfo/python-announce-list Support the Python Software Foundation: http://www.python.org/psf/donations.html
Re: Python for a 10-14 years old?
You might like the book Mindstorms, by Seymour Papert. The intro is here: http://www.papert.org/articles/GearsOfMyChildhood.html -- http://mail.python.org/mailman/listinfo/python-list
Re: embedded python example: PyString_FromString doesnt work?
On Thu, 24 Mar 2005 21:12:18 + David Harris wrote:
DH int
DH main(int argc, char *argv[])
DH {
DH PyObject *pName, *s, *pModule, *pDict, *pFunc;
DH PyObject *pArgs, *pValue;
DH int i;
DH
DH if (argc 3) {
DH fprintf(stderr,Usage: call pythonfile funcname [args]\n);
DH return 1;
DH }
DH
DH
DH Py_Initialize();
[...]
DH Calling the program gives an error;
DH [EMAIL PROTECTED]:~/source/python ./test_String script1.py multiply 4
DH 5 import went bang...
DH ImportError: No module named script1.py
DH script1.py exists and it is in the same directory as the executable
DH so its not a path error or that kind of stuff.
I believe you have to call Py_SetProgramName before Py_Initialize, or
otherwise let Python know that it should look for modules in this
directory. See http://python.org/doc/current/api/embedding.html#l2h-40
--
Denis S. Otkidach
http://www.python.ru/ [ru]
--
http://mail.python.org/mailman/listinfo/python-list
Re: Anonymus functions revisited : tuple actions
Kay Schluehr [EMAIL PROTECTED] wrote: To make my intention clear for another time, also for George who mistrusts these exercises alltogether. I want to derive a syntax and semantics for anonymus functions ( called tuple-actions ) that are generalizations of rules that are already used implicitely within Python e.g. tuple-unpacking. This is done by progressive interpretation and extension. They are not there by means of an accident, what Guido claims about the current lambda which he feels to be sticked onto the language. Regards, Kay I'd be glad to see a well-formulated view of the proposed tuple actions, provided I (and suspect others) can get through the syntax burden first. Expressions such as While((i)-(0), (i)-i3, (i)-(i+1), (res)-(res+i**2)) do not remind me the python I know and love. Alternatively, if it's not easy to come up with a grokable syntax, I would still be ok with it if it remained under the hood for the most part, like other obscure features such as metaclasses and descriptors; for instance I wouldn't mind at all if the traditional control flow primitives were implemented as functions using your idea, as long as I didn't have to know the details (and as long as other things, e.g. execution speed, were the same). As for the forthcoming - as it seems - deprecation or removal of lambdas, I'm in the minority that thinks it's a step in the wrong direction. The way they ended up in the language may be a historic accident, but I would favor a solution that improved them instead of removing them. The notion of 'anonymous functions' alone reveals a misconception in my opinion: that functions *have to* have a name to be 'normal'. Still, a name is just a binding to an object that exists independently of the name. We don't find 'anonymous strings', tuples, lists, etc. bad, so why should functions be different ? In this respect, functions are not 100% first class objects. Instead of removing lambdas, I would prefer to see them upgraded, perhaps with a new syntax, accepting more than one expressions and statements instead of a single expression. Sure, one can define named functions locally to avoid polluting the global scope, but why should he ? Just imagine how would python look like with a similar rule for other primitive types. Anyway, I guess I can live without lambdas but I'll miss them. George -- http://mail.python.org/mailman/listinfo/python-list
Re: Queue.Queue-like class without the busy-wait
Op 2005-03-24, Paul L. Du Bois schreef [EMAIL PROTECTED]: Has anyone written a Queue.Queue replacement that avoids busy-waiting? It doesn't matter if it uses os-specific APIs (eg WaitForMultipleObjects). I did some googling around and haven't found anything so far. I started once, using the Timer class in the Threading Module to break the lock. However the Timer class uses the same kind of sleep-polling loop, to delay the exection and allow an intermediate cancel, as the loop that is used in Queue.Queue, so that was no gain. I have still played with the idea, but haven't worked anything out since then. -- Antoon Pardon -- http://mail.python.org/mailman/listinfo/python-list
Grouping code by indentation - feature or ******?
What do you guys think about Python's grouping of code via indentation? Is it good - perhaps because it saves space and eliminates keypresses? Or is it bad - perhaps because it makes program flow dependent on invisible, and unpronouncable characters - and results in more manual alignment issues by preventing code formatters from managing indentation? Python is certainly pretty unorthodox in this area. How would you have dealt with the issue of how to group statements? -- __ |im |yler http://timtyler.org/ [EMAIL PROTECTED] Remove lock to reply. -- http://mail.python.org/mailman/listinfo/python-list
Re: Grouping code by indentation - feature or ******?
Tim Tyler wrote: What do you guys think about Python's grouping of code via indentation? This is a Python newsgroup. Assume that we all have been brainwashed. How would you have dealt with the issue of how to group statements? Off the top of my head I can think of one other way: associate a wav file with every grouping level and have your editor play it while you are editing that particular level. I think that would be very effective to get a Pythonista acknowledge the merits of C/Pascal grouping markers -- noisy, but not *that* noisy... Peter -- http://mail.python.org/mailman/listinfo/python-list
Re: Python docs [was: function with a state]
Xah Lee wrote: The Python doc is relatively lousy, from content organization to the tech writing quality. So write your own or fork the current one. I doubt if that's a problem. Did you read Dive into Python? -- John Small Perl scripts: http://johnbokma.com/perl/ Perl programmer available: http://castleamber.com/ Happy Customers: http://castleamber.com/testimonials.html -- http://mail.python.org/mailman/listinfo/python-list
Re: Python docs [was: function with a state]
Martin Ambuhl wrote: Apologies to these various newsgroups, but I have no idea which one Xah Lee actually reads or posts from. F'ups set. Probably none, since they are all crowded with crazy linux zealots :-D. -- John Small Perl scripts: http://johnbokma.com/perl/ Perl programmer available: http://castleamber.com/ Happy Customers: http://castleamber.com/testimonials.html -- http://mail.python.org/mailman/listinfo/python-list
Re: Queue.Queue-like class without the busy-wait
Antoon Pardon [EMAIL PROTECTED] writes: I started once, using the Timer class in the Threading Module to break the lock. However the Timer class uses the same kind of sleep-polling loop, to delay the exection and allow an intermediate cancel, as the loop that is used in Queue.Queue, so that was no gain. I've never checked this code but it wouldn't have occurred to me that Queue uses any kind of timeout loop. Can't it work the obvious way with a semaphore? -- http://mail.python.org/mailman/listinfo/python-list
Re: Distributing closed source modules
Dave Brueck wrote:
Jiri Barton wrote:
[snip..]
Hello Dave,
Protecting code in any language is pretty tough and/or futile, but
you can
Google the archives if you're interested in reading more on that.
It's certainly something lot's of people are interested in. I guess it
depends who your audience is. If ytour code isn't for *mass*
distribution - the chances of people putting a lot of effort into
breaking it are greatly reduced. I don't htink it's necessarily futile.
Anyway, you can create a module on the fly like this (untested):
import new, sys
name = 'MyModule'
m = sys.modules[name] = new.module(name)
exec codeStr in m.__dict__
where codeStr is a string that contains the source code of your
module (e.g.
from file('somemodule.py').read() ).
This is one of the better solutions I've seen. (Probably because it's
*not* very complex). The stored modules can be well encrypted.
Obviously the decryption code will be in the main code - but I guess it
can be obfuscated pretty well.
I like it.
Regards,
Fuzzy
http://www.voidspace.org.uk/python
You can combine the above with whatever mechanism you come up with
for
distributing the code itself. You could store it in an encrypted
archive file,
you could download it on the fly from a remote server over a secure
connection, etc.
-Dave
--
http://mail.python.org/mailman/listinfo/python-list
Re: Queue.Queue-like class without the busy-wait
Op 2005-03-25, Paul Rubin schreef http: Antoon Pardon [EMAIL PROTECTED] writes: I started once, using the Timer class in the Threading Module to break the lock. However the Timer class uses the same kind of sleep-polling loop, to delay the exection and allow an intermediate cancel, as the loop that is used in Queue.Queue, so that was no gain. I've never checked this code but it wouldn't have occurred to me that Queue uses any kind of timeout loop. Can't it work the obvious way with a semaphore? And how is this semaphore going to be released if the timeout is reached? -- Antoon Pardon -- http://mail.python.org/mailman/listinfo/python-list
Re: embedded python example: PyString_FromString doesnt work?
wierd. does: http://www.python.org/doc/2.3.2/ext/pure-embedding.html work for you ? Yes. It does. ./test_String script1.py multiply 4 5 Don't run it with the .py suffix. The argv[1] is a module name, not a filename.. Even if you do, it may not find the module. Depending of what you have in PYTHONPATH. Try also: export PYTHONPATH=. I believe you have to call Py_SetProgramName before Py_Initialize, Yes. This is another way to affect the search path. BranoZ -- http://mail.python.org/mailman/listinfo/python-list
POST data with 401 authentication using urllib(2)
Hi all,
I'm trying to submit some data using a POST request to a HTTP server with
BASIC authentication with python, but I can't get it to work. Since it's
driving me completely nuts, so here's my cry for help.
The server is an elog logbook server (http://midas.psi.ch/elog/). It is
protected with a password and an empty username. I can login both using
urllib and urllib2 (suppose the password is foobar, the logbook is
running on port 8181, and I need the directory Artikelen)
urllib:
class AuthenticatedURL(urllib.FancyURLopener) :
def prompt_user_passwd(this, host, realm):
return(, foobar)
url = AuthenticatedURL()
data =
f = url.open(http://localhost:8181/Artikelen;)
urllib2:
auth_handler = urllib2.HTTPBasicAuthHandler()
auth_handler.add_password('Artikelen', 'localhost:8181', '', 'foobar')
opener = urllib2.build_opener(auth_handler) urllib2.install_opener(opener)
f = urllib2.urlopen('http://localhost:8181/Artikelen')
So far so good. But I want to submit some data via CGI. I can do this by
making a GET request out of the URL:
f = url.open(http://localhost:8181/Artikelen/?cmd=Submitreply_to=80;)
This works as advertised (also with urllib2).
However, since I also need to upload files, I want to do this via a POST
request (as it is donenormally via the web interface). However, if I try
this using either urllib or urllib2, it throws an exception:
data = {cmd : Submit, reply_to : 80}
urllib:
f = url.open(http://localhost:8181/Artikelen/;, urllib.urlencode(data))
Traceback (most recent call last):
File login.py, line 12, in ?
f = url.open(http://pde.dyndns.org:8181;, data)
File /usr/lib/python2.3/urllib.py, line 183, in open
return getattr(self, name)(url, data)
File /usr/lib/python2.3/urllib.py, line 308, in open_http
return self.http_error(url, fp, errcode, errmsg, headers, data)
File /usr/lib/python2.3/urllib.py, line 323, in http_error
return self.http_error_default(url, fp, errcode, errmsg, headers)
File /usr/lib/python2.3/urllib.py, line 551, in http_error_default
return addinfourl(fp, headers, http: + url)
File /usr/lib/python2.3/urllib.py, line 837, in __init__
addbase.__init__(self, fp)
File /usr/lib/python2.3/urllib.py, line 787, in __init__
self.read = self.fp.read
AttributeError: 'NoneType' object has no attribute 'read'
urllib2:
f = urllib2.urlopen('http://localhost:8181/Artikelen/',
urllib.urlencode(data))
Traceback (most recent call last):
File login2.py, line 11, in ?
f = urllib2.urlopen('http://localhost:8181/Artikelen/', data)
File /usr/lib/python2.3/urllib2.py, line 129, in urlopen
return _opener.open(url, data)
File /usr/lib/python2.3/urllib2.py, line 326, in open
'_open', req)
File /usr/lib/python2.3/urllib2.py, line 306, in _call_chain
result = func(*args)
File /usr/lib/python2.3/urllib2.py, line 901, in http_open
return self.do_open(httplib.HTTP, req)
File /usr/lib/python2.3/urllib2.py, line 895, in do_open
return self.parent.error('http', req, fp, code, msg, hdrs)
File /usr/lib/python2.3/urllib2.py, line 346, in error
result = self._call_chain(*args)
File /usr/lib/python2.3/urllib2.py, line 306, in _call_chain
result = func(*args)
File /usr/lib/python2.3/urllib2.py, line 659, in http_error_401
host, req, headers)
File /usr/lib/python2.3/urllib2.py, line 638, in http_error_auth_reqed
return self.retry_http_basic_auth(host, req, realm)
File /usr/lib/python2.3/urllib2.py, line 648, in retry_http_basic_auth
return self.parent.open(req)
File /usr/lib/python2.3/urllib2.py, line 326, in open
'_open', req)
File /usr/lib/python2.3/urllib2.py, line 306, in _call_chain
result = func(*args)
File /usr/lib/python2.3/urllib2.py, line 901, in http_open
return self.do_open(httplib.HTTP, req)
File /usr/lib/python2.3/urllib2.py, line 895, in do_open
return self.parent.error('http', req, fp, code, msg, hdrs)
File /usr/lib/python2.3/urllib2.py, line 352, in error
return self._call_chain(*args)
File /usr/lib/python2.3/urllib2.py, line 306, in _call_chain
result = func(*args)
File /usr/lib/python2.3/urllib2.py, line 412, in http_error_default
raise HTTPError(req.get_full_url(), code, msg, hdrs, fp)
urllib2.HTTPError: HTTP Error -1:
In fact, I get these exact same errors if data is empty. I'm
wondering if this is supported in python. I can't find anything about it
in TFM. If it's not supported, does anybody have an idea how to do it? If
it is supported, can anybody tell what I'm dowing wrong?
Any help is greatly appreciated.
Pieter Edelman
--
http://mail.python.org/mailman/listinfo/python-list
Re: Python docs [was: function with a state]
In comp.lang.perl.misc Xah Lee [EMAIL PROTECTED] wrote: The Python doc is relatively lousy, from content organization to the tech writing quality. Which has precisely what to do with most of the groups to which you cross-posted? Problem: They all have the same priority (which is higher than that of the Boolean operations). However, the ?they? pronoun from the context of previous sentence, refers to ?the comparison operation?, not ?operator?. So, it conjures the reader to think about some ?operation precedence?, which in itself cannot be ruled out as nonsense depending on the context. Very fucking stupid confusional writing. The meaning is perfectly plain. By the way did you perhaps mean 'confusing' or 'confused'? I normally regard language flames otiose but here, since you are trying to correct other people's writing, fair game. And, from pure writing aspect, the sentence ?...(which is ...)? is some kind of a juvenile latch on. If the author intent to make that Do you mean... 'if the author's intent is to make' or 'if the author intends to'? point, say it in its own sentence. e.g. The comparison operators have higher precedence than boolean operators. It would be better to not mention this at all. For practical considerations, very rare is the case of mixing boolean and comparison operators, and if so, parenthesis are likely used and is indeed a good practice. The proper place for Should that not be 'parentheses are likely to be used'? It is not rare at all. Besides, little asides like this are an ideal way to reinforce thoughts about operator preference and more helpful then memorising a table. Problem: Comparisons can be chained arbitrarily; for example, x y = z is equivalent to x y and y = z, except that y is evaluated only once (but in both cases z is not evaluated at all when x y is found to be false). Drop the word ?arbitrarily?. It has no meaning here. I suggest you look up the meaning of the word. the whole sentence is one fucked up verbiage of pell-mell thinking and writing. Here's one example of better: Comparisons can be chained, and is evaluated from left to right. For example, x y = z is equivalent to (x y) = z. You mean 'are evaluated'. Your rephrasing is also incomplete since it doesn't note that z will not be evaulated if x y is false. With respect to documentation style, it is questionable that this aspect needs to be mentioned at all. In practice, if programers need to chain comparisons, they will readily do so. This is not out of ordinary in imperative languages, and evaluation from left to right is also not extraordinary to cost a mention. Really? In a reference manual such matters should be fully specified regardless of what happens in other languages. Problem: and != are alternate spellings for the same operator. != is the preferred spelling; is obsolescent In general, when something is obsolete or might go defunct in the future, consider not even mentioning that construct. If necessary, add it in a obscure place, and not adjacent to critical info. In many places of Python documentation, this is breached. Really? Actually it is very important to mention it in the correct place in a reference manual. Do you understand the concept of maintaining old code? I'm in fact somewhat surprised by this poor quality in writing. The Really? The writing in the manual seems simple, straight-forward and clear to me (knowing no Python). Unlike your writing. more egregious error is the hardware-oriented organization aka technical drivel. What on earth does this mean? The Python doc, though relatively incompetent, but the author have tried the best. This is in contrast to documentations in unix related things (unix tools, perl, apache, and so on etc), where the writers have absolutely no sense of clear writing, and in most cases don't give a damn and delight in drivel thinking of it as literary. I think that this is an excellent description of your own writing. Axel -- http://mail.python.org/mailman/listinfo/python-list
Re: embedded python example: PyString_FromString doesnt work?
On Fri, 25 Mar 2005 11:09:35 +0300, Denis S. Otkidach wrote:
DH Calling the program gives an error;
DH [EMAIL PROTECTED]:~/source/python ./test_String script1.py multiply 4
DH 5 import went bang...
DH ImportError: No module named script1.py
DH script1.py exists and it is in the same directory as the executable
DH so its not a path error or that kind of stuff.
I believe you have to call Py_SetProgramName before Py_Initialize, or
otherwise let Python know that it should look for modules in this
directory. See http://python.org/doc/current/api/embedding.html#l2h-40
excellent!! that was the tip (+ PySys_SetArgv) the worked ...
This now works:
int
main(int argc, char *argv[])
{
PyObject *pName, *s, *pModule, *pDict, *pFunc;
PyObject *pArgs, *pValue;
int i;
Py_SetProgramName(argv[0]);
Py_Initialize();
PySys_SetArgv(argc, argv);
pName = PyString_FromString(argv[1]);
...
}
Thanks a bunch denis :)
--
http://mail.python.org/mailman/listinfo/python-list
Re: An Abridged Python Tutorial
Michael Spencer wrote:
An Abridged Python Tutorial
(snip fine piece of art)
applaude
--
bruno desthuilliers
python -c print '@'.join(['.'.join([w[::-1] for w in p.split('.')]) for
p in '[EMAIL PROTECTED]'.split('@')])
--
http://mail.python.org/mailman/listinfo/python-list
Re: Queue.Queue-like class without the busy-wait
Antoon Pardon [EMAIL PROTECTED] writes: I've never checked this code but it wouldn't have occurred to me that Queue uses any kind of timeout loop. Can't it work the obvious way with a semaphore? And how is this semaphore going to be released if the timeout is reached? I meant a semaphore to synchronize the queue when adding or removing objects. Timeout would be handled with sigalarm or select. -- http://mail.python.org/mailman/listinfo/python-list
Re: Anonymus functions revisited
Ron wrote:
It's interesting that there is a whole is_type_() group of functions
in the inspect module, but not a is_defined(). Maybe I just haven't
found it yet.
I've never found any need for an is_defined function. If in doubt I just
make sure and initialise all variables to a suitable value before use.
However, I'll assume you have a good use case.
#
def if_not_defined(v, dv=None, lv=locals()):
if lv.has_key(v):
return lv[v]
return dv
I don't see the point of the default argument. locals() at the global level
simply returns globals, so you might as well use that. A more useful
default would be the caller's locals.
def is_defined(v, lv=locals()):
if lv.has_key(v):
return True
False
Same comments, plus the whole 'if on a boolean to return a boolean' is a
bit redundant.
Try something on these lines:
import inspect
def is_defined(name, lv=None):
if lv is None:
lv = inspect.currentframe().f_back.f_locals
return name in lv
is_defined('abc')
False
abc = 3
is_defined('abc')
True
def f(x):
print is_defined('x')
print is_defined('y')
y = 0
print is_defined('y')
f(2)
True
False
True
# Shorten names and pass locals() with lambas for
# convenience. (This needs to be in the function
# where they are used or it will break.
# Another use for lamba! ;)
ifnd = lambda v, dv, lv=locals(): if_not_defined(v,dv,lv)
isa = lambda v, lv=locals(): is_defined(v, lv)
There is no need for lambda here, it adds nothing. Use a 'def'.
--
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Re: Queue.Queue-like class without the busy-wait
Op 2005-03-25, Paul Rubin schreef http: Antoon Pardon [EMAIL PROTECTED] writes: I've never checked this code but it wouldn't have occurred to me that Queue uses any kind of timeout loop. Can't it work the obvious way with a semaphore? And how is this semaphore going to be released if the timeout is reached? I meant a semaphore to synchronize the queue when adding or removing objects. Last I looked there was a lock used for that. The loop is only for when you cant remove or add an element immediatly and there is a timeout. Timeout would be handled with sigalarm or select. How is select going to help? IMO you can't put a Queue in a select call. And it is doubtfull if working with sigalarm will do the trick. First of all is the problem the signal module in python is very limited. IIRC all signals are routed to the main thread. So breaking a lock by having the thread signaled is impossible in python. You may provide your own signal module, but that may not be enough. The last time I experimented with a pthreads in C, locks didn't break by signalling the thread. That might be a bug, but I wouldn't know since I'm not familiar with the pthread specifications. -- Antoon Pardon -- http://mail.python.org/mailman/listinfo/python-list
Re: winapi32.GetFileVersionInfo() - problem
snip the fourth and hopefully last repost Do you actually think anybody will reply to your mail if you keep reposting at this frequency? It'll rather make most people here kill-file you. One post is enough; we've seen your problem, and it seems as though nobody here has a better solution than what Dennis Lee Bieber has already offered. Just to make sure you understand what he said, I'll repeat it here: Your DLL doesn't contain a resources section, which in turn contains the version information you're asking for. So, please start reading MSDN and the VC++ documentation on how to add this information to your DLL. If you wish to catch the exception that's raised (because the resource block isn't present), use something like the following: try: d = win32api.GetFileVersionInfo(fname,r\) except: d = None if d is None: print No version info in file! else: do something with the version info -- --- Heiko. pgpcvIOsraTHA.pgp Description: PGP signature -- http://mail.python.org/mailman/listinfo/python-list
Re: Queue.Queue-like class without the busy-wait
Antoon Pardon [EMAIL PROTECTED] writes: I meant a semaphore to synchronize the queue when adding or removing objects. Last I looked there was a lock used for that. OK, that amounts to the same thing. The loop is only for when you cant remove or add an element immediatly and there is a timeout. Timeout would be handled with sigalarm or select. How is select going to help? IMO you can't put a Queue in a select call. And it is doubtfull if working with sigalarm will do the trick. You could open a socket to your own loopback port and then select on it, or something like that. The select call takes a timeout parameter. First of all is the problem the signal module in python is very limited. IIRC all signals are routed to the main thread. So breaking a lock by having the thread signaled is impossible in python. A signal handler in the main thread could release a lock that the thread is waiting on. -- http://mail.python.org/mailman/listinfo/python-list
Re: [newbie] smtplib.login()?
On Mar 25, 2005, at 11:04, PA wrote: What am I doing wrong? Why is the user name being encoded twice? Ok... turns out that this is/was a bug in the python smtplib as recently as Dec 6 2004: Patch #1075928: AUTH PLAIN in smtplib. smtplib can not log in to some server using command AUTH PLAIN, it sends ``user\0user\0pass'' to the server, but ``\0user\0pass'' has better compatibility. http://cvs.sourceforge.net/viewcvs.py/python/python/dist/src/Lib/ smtplib.py Sigh... Cheers -- PA, Onnay Equitursay http://alt.textdrive.com/ -- http://mail.python.org/mailman/listinfo/python-list
SimpleRPCServer
I am trying to restrict some of the methods available by RPC to whether the user is connected through a ssh-tunnel eg. connecting from localhost. class UserRPC: '''Methods available to users''' pass class AdminRPC(UserRPC): '''Methods available only when connecting from localhost''' pass class RPCServer(SimpleXMLRPCServer): def _dispatch(self, method, args): if user_is_connecting_from_localhost(): return getattr(AdminRPC(), method)(*args) return getattr(UserRPC(), method)(*args) What i don't know is how to the client ip. I would think I should override the _marshalled_dispatch method but I can't quite grasp it all. /Esben -- http://mail.python.org/mailman/listinfo/python-list
gnuplot -reverse
Experimenting with the gnuplot package under Debian Linux, I've found that the -reverse option when used to start gnuplot from the command-line will produce plots that are color-reversed and render with white text on a black background However, I'm too dense to see how to easily achieve the same effect when using the python-gnuplot package Any clues would be greatly appreciated -- Stanley C. Kitching Human Being Phoenix, Arizona -- http://mail.python.org/mailman/listinfo/python-list
Re: Queue.Queue-like class without the busy-wait
Op 2005-03-25, Paul Rubin schreef http: Antoon Pardon [EMAIL PROTECTED] writes: I meant a semaphore to synchronize the queue when adding or removing objects. Last I looked there was a lock used for that. OK, that amounts to the same thing. The loop is only for when you cant remove or add an element immediatly and there is a timeout. Timeout would be handled with sigalarm or select. How is select going to help? IMO you can't put a Queue in a select call. And it is doubtfull if working with sigalarm will do the trick. You could open a socket to your own loopback port and then select on it, or something like that. The select call takes a timeout parameter. Well maybe you could use an os.pipe as a timeout lock then. When the lock is instantiated you put one byte in it. Aquiring the lock is implemented by reading one byte, releasing the lock is implemented by writing a byte. Aquiring the lock with a timeout would make use of select. It would require carefull coding, since you want to prevent the thread blocking because of select returning indicating it could be read, but between the select and the actual read an other thread already consumed the byte. First of all is the problem the signal module in python is very limited. IIRC all signals are routed to the main thread. So breaking a lock by having the thread signaled is impossible in python. A signal handler in the main thread could release a lock that the thread is waiting on. This wouldn't work. A thread would have no way knowing for what purpose the lock was released, because the lock was released by the thread holding the lock or because the signal handler released the lock, both would look the same for the thread aquiring the lock. There is also the problem you can't direct which thread will aquire the lock. Suppose you have two threads waiting on a lock, one plain, one with a timeout. Your signal handler kicks in and releases the lock. There is a good chance the first thread will now aquire the thread and the thread that used a timeout will continue to be blocked. -- http://mail.python.org/mailman/listinfo/python-list
How to move insert to position in Text widget (Tkinter)
I am working on a Find Text dialog box. Once you find a string in a Text widget, how do you at least move the cursor to that index (position)? Even better how can one 'select' the string one finds? ---code--- def searchText(): while 1: pos = self.mainEdit.search(findString.get(), 1.0, stopindex=END) if not pos: break print pos start = pos + +1c break ---end code--- thanks, Harlin Seritt -- http://mail.python.org/mailman/listinfo/python-list
modern kjbuckets anywhere?
I'm trying to get pySimplex working in Python 2.4, but I find that kjbucketsmodule.c makes reference to rename2.h which doesn't seem to be present in Python 2.4. I suppose that kjbucketsmodule.c needs to be brought up to date. It occurs to me that someone may have already done this so is there a modern version of the source on the web somewhere? -- Robin Becker -- http://mail.python.org/mailman/listinfo/python-list
Re: Archives and magic bytes
This is something I've recently thought about; perhaps you wouldn't mind some points? 1) I've been running 'file' via os.popen, and I've had trouble with it incorrectly spotting file types (Fedora Core 1). I can name a specific example where it thinks a plain text README file is HTML (despite that the configuration file for 'file' at least looks right). That makes me suspicious of its ability to spot more obscure types. (No, I haven't tried to get the latest 'file'; the days are long but they are filled with negative time and in the end I don't always get done what I should.) 2) Watch out for someone giving you, say, a bogus /bin/ls in a .zip file. You may want to look into chroot (which I believe requires you to run as root), or at least examine the output of unzip -l 3) You might also have to worry about the possibility that unpacking a bundle will fill up your disk's partition. At least for a while you hold both the bundle and the unpacked bundle. 4) Using os.popen to unpack the bundle has a lot of advantages, including that during debugging you can test the stuff from the command line and feel that you completely understand which steps are working (I think I use popen2, IIRC, and capture stderr for error messages). Perhaps this is mostly a reflection on me as a programmer :-} but I found the job surprisingly tricky. Jim -- http://mail.python.org/mailman/listinfo/python-list
Re: modern kjbuckets anywhere?
Robin Becker wrote: I'm trying to get pySimplex working in Python 2.4, but I find that kjbucketsmodule.c makes reference to rename2.h which doesn't seem to be present in Python 2.4. I suppose that kjbucketsmodule.c needs to be brought up to date. It occurs to me that someone may have already done this so is there a modern version of the source on the web somewhere? seems that gadfly.sf.net might be what I'm looking for -- Robin Becker -- http://mail.python.org/mailman/listinfo/python-list
Re: How to move insert to position in Text widget (Tkinter)
Harlin Seritt wrote: I am working on a Find Text dialog box. Once you find a string in a Text widget, how do you at least move the cursor to that index (position)? widget.mark_set(INSERT, pos) Even better how can one 'select' the string one finds? widget.tag_add(SEL, pos, endpos) to remove an existing selection, use widget.tag_remove(SEL, 1.0, END) /F -- http://mail.python.org/mailman/listinfo/python-list
Interface selection
Hello, How can I select on wich interface a socket will connect to? Say I have a pc with one network card and a 56K modem, how can I select on wich interface will the socket connect? Thank you -- http://mail.python.org/mailman/listinfo/python-list
Re: Grouping code by indentation - feature or ******?
What do you guys think about Python's grouping of code via indentation? Peter This is a Python newsgroup. Assume that we all have been Peter brainwashed. +1 QOTW. Skip -- http://mail.python.org/mailman/listinfo/python-list
Re: How to move insert to position in Text widget (Tkinter)
Frederik, Thanks! Just looking at your site (effbot and pythonware). I don't know what I'd do without it! Cheers, Harlin -- http://mail.python.org/mailman/listinfo/python-list
Re: Grouping code by indentation - feature or ******?
Op 2005-03-25, Tim Tyler schreef [EMAIL PROTECTED]: What do you guys think about Python's grouping of code via indentation? Is it good - perhaps because it saves space and eliminates keypresses? I think it was a mistake, but I'm probably in the minority here. -- Antoon Pardon -- http://mail.python.org/mailman/listinfo/python-list
Re: Interface selection
[EMAIL PROTECTED] wrote: Hello, How can I select on wich interface a socket will connect to? Say I have a pc with one network card and a 56K modem, how can I select on wich interface will the socket connect? you need to specify the ip address that interface has been assigned to in the bind-call. -- Regards, Diez B. Roggisch -- http://mail.python.org/mailman/listinfo/python-list
Re: SimpleRPCServer
Esben What i don't know is how to the client ip. I would think I should Esben override the _marshalled_dispatch method but I can't quite grasp Esben it all. First, from my reading of SimpleXMLRPCServer, I don't think _dispatch() belongs at that level. It belongs in the request handler class or in a separate dispatcher class, depending on what version of Python you're using. Second, SimpleXMLRPCServer is a SocketServer subclass. You should be able to provide a verify_request method (see the SocketServer docs) and a handler class with a set_local method: class RPCServer(SimpleXMLRPCServer): def verify_request(self, handler, address): handler.set_local(address_is_local(address)) A _dispatch method in the handler will then be able to check an attribute to know if the request was made from the local machine or not. Skip -- http://mail.python.org/mailman/listinfo/python-list
Re: Interface selection
Actually its not a server. I dont do any binding call, just a connect. -- http://mail.python.org/mailman/listinfo/python-list
Re: Grouping code by indentation - feature or ******?
Antoon Pardon [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] Op 2005-03-25, Tim Tyler schreef [EMAIL PROTECTED]: What do you guys think about Python's grouping of code via indentation? Is it good - perhaps because it saves space and eliminates keypresses? I think it was a mistake, but I'm probably in the minority here. Um, why? I think it isn't quite what's needed, based on the observation that it makes shifting from expression to statement context difficult enough that useful features like blocks don't have a decent syntax. On the other hand, it saves me an awful lot of hassle; it's one less thing to have to get into my head. John Roth -- Antoon Pardon -- http://mail.python.org/mailman/listinfo/python-list
Re: DBAPI Paramstyle
On Thu, 24 Mar 2005 15:03:13 +0100, Fredrik Lundh [EMAIL PROTECTED] \ wrote: Bob Parnes wrote: I must be missing something, so perhaps someone can explain the benefit of a paramstyle over the usual Python formatting style and maybe suggest a test to show it. Thanks. set the parameter to 0; DROP DATABASE template1; and see what happens. or set it to os.urandom(1000) and run your test a couple of times to see what happens. Thanks for the suggestion. My system does not appear to contain an os.urandom() method. It has a /dev/urandom device, but I don't know how to use it for this purpose, except perhaps to select the first byte that it produces. I have a mediocre talent at programming, which is why I chose python. For me it was a good choice. I note this so that I hope you understand why I say that I don't know what you are driving at. My understanding is that a paramstyle is more efficient than the traditional python approach for repeated use of a query. If so, then I do not see how the choice of a parameter is relevant. If it is more efficient only in a specific abstract case, then one would have to look for other reasons to use it in a practical application. Bob Parnes -- Bob Parnes [EMAIL PROTECTED] -- http://mail.python.org/mailman/listinfo/python-list
Re: Grouping code by indentation - feature or ******?
Tim Tyler wrote: What do you guys think about Python's grouping of code via indentation? Is it good - perhaps because it saves space and eliminates keypresses? Or is it bad - perhaps because it makes program flow dependent on invisible, and unpronouncable characters - and results in more manual alignment issues by preventing code formatters from managing indentation? http://www.python.org/doc/faq/general.html#why-does-python-use-indentation-for-grouping-of-statements from __future__ import braces File stdin, line 1 SyntaxError: not a chance Love it or leave it... Kent -- http://mail.python.org/mailman/listinfo/python-list
Re: Python for a 10-14 years old?
Leif B. Kristensen wrote: R.Meijer wrote: Jot jot at nad.com writes: If she's really gifted i hope she dumps that obsolete monolithic kernel as soon as she realizes that such beautiful language as python shouldn't be used on top of ugly, badly designed software. Did somebody say off-topic? I'd say it's a Troll -1. Anyway, that'd be my moderator response over at Slashdot. As had been said so many times; GNU/Hurd is still a pipe-dream. Those who think that the Linux kernel is based on faulty concepts should really get their act together and produce their own microkernel. Personally, I don't care about the kernel architecture as long as I've got a system that works right here, now. Anyway, I myself am 14 years old and I can make simple python scripts already by learning it off the official tutorial that comes with it. My tip: let her take her time with a normal adult tutorial, and give her small assignments every few chapters just so she gets it. If I may ask, do you think that the How to think like a Computer Scientist is a good starter? I'm 52 years old and learned my basics with Swan's Mastering Turbo Pascal 5.5 way back when, but I'm sincerely wondering what your generation think are hi-class tutorials. I've got a thirteen-year old daughter to whom I have recently taught the HTML basics, but she doesn't readily take to actual programming. If you've got any idea what I should push to her to get her fascinated about _real_ programming, I'd be obliged. Or maybe her head isn't screwed together that way, what do I know. I found How to Think Like a Computer Scientist a very good book. It was very well written and didn't push too many things onto you at once. -- -- Lucas Raab lvraab located at earthlink.net dotpyFE located at gmail.com AIM:Phoenix11890 MSN:dotpyfe @ gmail.com IRC:lvraab ICQ:324767918 Yahoo: Phoenix11890 -- http://mail.python.org/mailman/listinfo/python-list
Re: Interface selection
[EMAIL PROTECTED] wrote: Actually its not a server. I dont do any binding call, just a connect. Then where is your problem? The two interfaces have been assigned distinct IPs, so connect to the appropriate one. -- Regards, Diez B. Roggisch -- http://mail.python.org/mailman/listinfo/python-list
Re: Grouping code by indentation - feature or ******?
Op 2005-03-25, John Roth schreef [EMAIL PROTECTED]: Antoon Pardon [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] Op 2005-03-25, Tim Tyler schreef [EMAIL PROTECTED]: What do you guys think about Python's grouping of code via indentation? Is it good - perhaps because it saves space and eliminates keypresses? I think it was a mistake, but I'm probably in the minority here. Um, why? 1) It makes it hard to see how many levels are dedented at the end of a suite, and sometime makes it difficult to see where the end of a suite is. If e.g. you are looking at the code spread over two pieces of paper, it is sometimes hard to see whether the suite ends at the end of the first page or not. 2) It makes it hard to introduce some kind of new syntax constructs. Sometimes its isn't clear what would be the best indentation scheme for a syntantical structure, or some usefull syntantical won't fall in the indentation scheme that python provides. I think it a shame that these consideration would limit what constructs get into python or not. 3) Sometimes the structure of the algorithm is not the structure of the code as written, people who prefer that the indentation reflects the structure of the algorithm instead of the structure of the code, are forced to indent wrongly. -- Antoon Pardon -- http://mail.python.org/mailman/listinfo/python-list
Re: Grouping code by indentation - feature or ******?
Tim Tyler wrote: What do you guys think about Python's grouping of code via indentation? Is it good - perhaps because it saves space and eliminates keypresses? Or is it bad - perhaps because it makes program flow dependent on invisible, and unpronouncable characters - and results in more manual alignment issues by preventing code formatters from managing indentation? Python is certainly pretty unorthodox in this area. How would you have dealt with the issue of how to group statements? -- __ |im |yler http://timtyler.org/ [EMAIL PROTECTED] Remove lock to reply. You might read Eric Raymond's Why Python? article [http://www.linuxjournal.com/article/3882] I would agree with him in that it just seems natural. -- http://mail.python.org/mailman/listinfo/python-list
[Tutor] Re: Reading text lines from a socket
[Reposting to the general list too] Lloyd Kvam wrote: Sockets deal with packetized data. The network protocols do not guarantee keeping the data in line oriented chunks - even if the data starts out that way. You need to deal with extracting lines from chunks. So long as the connection is working properly, this is easy. The challenge occurs when the remainder of a line never gets delivered. The best strategy depends upon the details of what you are doing. I understand that. In Python using sockets is like using sockets in C. However, I was looking for a python equivalent of the perl idiom of opening a socket and getting a file handle ... and then reading this file handle as any other line oriented file using $socket-readline I am trying to write a simple Netcraft style script which tries the HEAD method on a webserver and reads the Server: header from the response. I would not like to use urllib, because even a call to something like urllib.info() reads in the complete webpage on an open(). Even if this particular problem could be done elegantly, I would be interested to know the answer to my original question because the feature of reading a line at a time from a socket will help me in a lot of other places in the future. - Sandip -- Sandip Bhattacharya sandip (at) puroga.com Puroga Technologies Pvt. Ltd. Work: http://www.puroga.comHome: http://www.sandipb.net GPG: 51A4 6C57 4BC6 8C82 6A65 AE78 B1A1 2280 A129 0FF3 ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor -- http://mail.python.org/mailman/listinfo/python-list
Re: [Tutor] Re: Reading text lines from a socket
Well, I've never used it, but sockets do have the makefile method. That would seem to fit what you're trying to do. Sandip Bhattacharya wrote: [Reposting to the general list too] Lloyd Kvam wrote: Sockets deal with packetized data. The network protocols do not guarantee keeping the data in line oriented chunks - even if the data starts out that way. You need to deal with extracting lines from chunks. So long as the connection is working properly, this is easy. The challenge occurs when the remainder of a line never gets delivered. The best strategy depends upon the details of what you are doing. I understand that. In Python using sockets is like using sockets in C. However, I was looking for a python equivalent of the perl idiom of opening a socket and getting a file handle ... and then reading this file handle as any other line oriented file using $socket-readline I am trying to write a simple Netcraft style script which tries the HEAD method on a webserver and reads the Server: header from the response. I would not like to use urllib, because even a call to something like urllib.info() reads in the complete webpage on an open(). Even if this particular problem could be done elegantly, I would be interested to know the answer to my original question because the feature of reading a line at a time from a socket will help me in a lot of other places in the future. - Sandip -- Lloyd Kvam Venix Corp. 1 Court Street, Suite 378 Lebanon, NH 03766-1358 voice: 603-653-8139 fax:801-459-9582 ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor -- http://mail.python.org/mailman/listinfo/python-list
Re: Grouping code by indentation - feature or ******?
Op 2005-03-25, Carl Banks schreef [EMAIL PROTECTED]: Tim Tyler wrote: What do you guys think about Python's grouping of code via indentation? Is it good - perhaps because it saves space and eliminates keypresses? It's good, but this is only a minor reason. The reason this is good is because it exactly reflects the way human beings mentally group code in their heads. In Python, you can eyeball grouping with 100% accuracy (except for one flaw that's being phased out). That is not true. You can with the innermost levels, but it isn't always that clear with intermediate levels. Not so with other languages. In other languages, you have two simultaneous ways of grouping code: the way that makes sense to humans (indentation), and the way (braces or begin/end). This creates the possibility of mismatch, and it puts an extra burden on the programmer to make sure computer and human grouping stays synchronized. Structure/Disciplined programming is a burden in general. I have never found putting braces or what ever delimiter such a problem. I don't see people argueing that putting the right number of parenthesis and or brackets is an extra burden. Grouping by indentations also goes a long way to prevent sloppiness. No matter how sloppy your style is, you can't slop away the way the way program was nested in Python; thus a reader should be able to follow the flow of just about any code. IMO the flow of a lot of code would be easier to follow if code like if condition: break could be dedented, because such a condition is really at the same level as the while I've ended up as the computer expert at my engineering firm, so I get (non-Python) code to debug from time to time, and I can attest that inconsistent style is the single worst thing that everyone does to make code unreadable. Python-like indentation would instantly halve that problem. Use a tool for that. If people want something in python that python doesn't has, those people are refered to tools that provide it. It it works in that direction, it should also work in the other direction and people that would like some feature of python in an other language should use a tool for that. You wnat consistent style? Use a tool to put all your source in a consistent style. The drawbacks are insanely minor. It makes one liners more difficult, and can result in transmission difficulties with some stupid programs that helpfully strip leading whitespace. (There's another drawback in Python that isn't inherent to grouping by indentation, namely the possibility of mixing spaces and tabs. This is the flaw that's being phased out.) Or is it bad - perhaps because it makes program flow dependent on invisible, It doesn't. I suspect Pythonistas will heavily attest to that. But, as I said, it does make it virtually impossible for sloppy code to mislead you about the flow. Overall, if someone hands you a random piece of C code, and a random piece of Python code, you will be more likely to easily follow the flow of the Python. Not with my own code. The difference is not great but my C programs have a slight edge here. How would you have dealt with the issue of how to group statements? Having experienced Python, I can say pretty earnestly that, were I designing my own language, there is no other way I would do it. Grouping by indentation is a slam dunk for me. Well to each his own. -- Antoon Pardon -- http://mail.python.org/mailman/listinfo/python-list
Re: Grouping code by indentation - feature or ******?
Tim Tyler wrote: What do you guys think about Python's grouping of code via indentation? Is it good - perhaps because it saves space and eliminates keypresses? It's good, but this is only a minor reason. The reason this is good is because it exactly reflects the way human beings mentally group code in their heads. In Python, you can eyeball grouping with 100% accuracy (except for one flaw that's being phased out). Not so with other languages. In other languages, you have two simultaneous ways of grouping code: the way that makes sense to humans (indentation), and the way (braces or begin/end). This creates the possibility of mismatch, and it puts an extra burden on the programmer to make sure computer and human grouping stays synchronized. Grouping by indentations also goes a long way to prevent sloppiness. No matter how sloppy your style is, you can't slop away the way the way program was nested in Python; thus a reader should be able to follow the flow of just about any code. I've ended up as the computer expert at my engineering firm, so I get (non-Python) code to debug from time to time, and I can attest that inconsistent style is the single worst thing that everyone does to make code unreadable. Python-like indentation would instantly halve that problem. The drawbacks are insanely minor. It makes one liners more difficult, and can result in transmission difficulties with some stupid programs that helpfully strip leading whitespace. (There's another drawback in Python that isn't inherent to grouping by indentation, namely the possibility of mixing spaces and tabs. This is the flaw that's being phased out.) Or is it bad - perhaps because it makes program flow dependent on invisible, It doesn't. I suspect Pythonistas will heavily attest to that. But, as I said, it does make it virtually impossible for sloppy code to mislead you about the flow. Overall, if someone hands you a random piece of C code, and a random piece of Python code, you will be more likely to easily follow the flow of the Python. and unpronouncable characters - and results in more manual alignment issues by preventing code formatters from managing indentation? This is true. Most common complaint is changing the nesting level of a block of code. Good editors have ways to cope with this, just as good editors have ways to cope with all these superfluous braces in other languages. Python is certainly pretty unorthodox in this area. How would you have dealt with the issue of how to group statements? Having experienced Python, I can say pretty earnestly that, were I designing my own language, there is no other way I would do it. Grouping by indentation is a slam dunk for me. -- CARL BANKS -- http://mail.python.org/mailman/listinfo/python-list
[perl-python] limericks
Better: there is a Python, pithy mighty, lissome, and tabby algorithms it puffs conundrums it snuffs and cherished by those savvy there is a camel, kooky ugly, petty, ungainly hacking it supports TIMTOWTDI it sports and transports DWIM-wit's fancy Xah [EMAIL PROTECTED] http://xahlee.org/PageTwo_dir/more.html -- http://mail.python.org/mailman/listinfo/python-list
Re: [newbie] smtplib.login()?
PA wrote: On Mar 25, 2005, at 11:04, PA wrote: What am I doing wrong? Why is the user name being encoded twice? Ok... turns out that this is/was a bug in the python smtplib as recently as Dec 6 2004: Patch #1075928: AUTH PLAIN in smtplib. smtplib can not log in to some server using command AUTH PLAIN, it sends ``user\0user\0pass'' to the server, but ``\0user\0pass'' has better compatibility. I'll try to look into it. -- Gerhard -- http://mail.python.org/mailman/listinfo/python-list
Re: Grouping code by indentation - feature or ******?
Structure/Disciplined programming is a burden in general. I have never found putting braces or what ever delimiter such a problem. I don't see people argueing that putting the right number of parenthesis and or brackets is an extra burden. Oh, not the right number. But I have seen wars waging over the correct indention style to use. Braces behind flow control statements, or beneath, and if the latter, indented halfways or not? Use a tool for that. If people want something in python that python doesn't has, those people are refered to tools that provide it. It it works in that direction, it should also work in the other direction and people that would like some feature of python in an other language should use a tool for that. You wnat consistent style? Use a tool to put all your source in a consistent style. And what to do if two (or more) people can't decide on what convention to use? And just in case you never worked with CVS: Having mutually commits of sourcecode that has been subject to code formatting tools often creates a hellhole of conflicts - which is a major PITA. Well to each his own. Amen. Why don't you use ruby? It has braces. And code blocks. And its more liberal towards overriding builtins, which might appeal to you. -- Regards, Diez B. Roggisch -- http://mail.python.org/mailman/listinfo/python-list
Re: Grouping code by indentation - feature or ******?
Op 2005-03-25, Diez B. Roggisch schreef [EMAIL PROTECTED]: Structure/Disciplined programming is a burden in general. I have never found putting braces or what ever delimiter such a problem. I don't see people argueing that putting the right number of parenthesis and or brackets is an extra burden. Oh, not the right number. But I have seen wars waging over the correct indention style to use. Braces behind flow control statements, or beneath, and if the latter, indented halfways or not? Use a tool for that. If people want something in python that python doesn't has, those people are refered to tools that provide it. It it works in that direction, it should also work in the other direction and people that would like some feature of python in an other language should use a tool for that. You wnat consistent style? Use a tool to put all your source in a consistent style. And what to do if two (or more) people can't decide on what convention to use? Normally one is the project leader. He decides. And just in case you never worked with CVS: Having mutually commits of sourcecode that has been subject to code formatting tools often creates a hellhole of conflicts - which is a major PITA. Well to each his own. Amen. Why don't you use ruby? It has braces. And code blocks. And its more liberal towards overriding builtins, which might appeal to you. I have other problems with it. I have problems with all languages currently available, so I use those which rub me wrong the least. I think the indentation syntax of python was a mistake, but for the most part it is a minor issue and it doesn't weight heavy enough to go and use an other language, although I keeping looking at the other languages. -- Antoon Pardon -- http://mail.python.org/mailman/listinfo/python-list
Re: Grouping code by indentation - feature or ******?
Normally one is the project leader. He decides. Whishful thinking. Another problem I have with code that is _not_ layouted the way I'm used to it is that the perception of what very code does gets more difficult to me. You seem to have the same troubles, I take that from your desire to reflect algorithmic structure different from syntactic. And I guess most people havo, otherwise the whose layout-thing wouldn't stir up so bad feelings all the time. And as not all code I read is code I'm supposed to write (might it be OSS that I dig into for debugging, or other 3rd party sources I can't control, e.g. different departments with different project leaders) I found that python's way of imposing a rather strict layout on _all_ coders out there means I've less trouble digging into other peoples code. Which is useful - and it seems that I'm not the only one with this feeling. -- Regards, Diez B. Roggisch -- http://mail.python.org/mailman/listinfo/python-list
Version Number Comparison Function
Is there a function for comparing version numbers? E.g. 0.1.0 0.1.2 1.876b 1.876c 3.2.2 3.4 Keith -- http://mail.python.org/mailman/listinfo/python-list
Re: Version Number Comparison Function
On 25 Mar 2005 07:34:38 -0800, rumours say that Keith [EMAIL PROTECTED] might have written: Is there a function for comparing version numbers? E.g. 0.1.0 0.1.2 1.876b 1.876c 3.2.2 3.4 Keith Convert your version numbers into tuples: (0, 1, 0) (0, 1, 2) (1, 876, 'b') (1, 876, 'c') (3, 2, 2) (3, 4) All of the above are True. -- TZOTZIOY, I speak England very best. Be strict when sending and tolerant when receiving. (from RFC1958) I really should keep that in mind when talking with people, actually... -- http://mail.python.org/mailman/listinfo/python-list
Re: Version Number Comparison Function
On 25 Mar 2005 07:34:38 -0800, Keith [EMAIL PROTECTED] wrote:
Is there a function for comparing version numbers?
E.g.
0.1.0 0.1.2
1.876b 1.876c
3.2.2 3.4
Not by default AFAIK. How about something like (untested):
def test_version(v1, v2):
v1, v2 = v1.split('.'), v2.split('.')
for x, y in zip(v1, v2):
if x y: return v1
if y x: return v2
It assumes that v1 and v2 have the same amount of '.'s and that all of
the version numbers are of the same length (i.e. 1.1000 would be
1.999). How general do you need to be?
Peace
Bill Mill
bill.mill at gmail.com
--
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Re: Version Number Comparison Function
Keith wrote: Is there a function for comparing version numbers? E.g. 0.1.0 0.1.2 1.876b 1.876c 3.2.2 3.4 the following works for many common cases: import re def cmpver(a, b): def fixup(i): try: return int(i) except ValueError: return i a = map(fixup, re.findall(\d+|\w+, a)) b = map(fixup, re.findall(\d+|\w+, b)) return cmp(a, b) # -1 if ab, 0 if a=b, 1 if ab cmpver(0.1.0, 0.1.2) -1 cmpver(1.876b, 1.876c) -1 cmpver(3.2.2, 3.4) -1 ymmv. /F -- http://mail.python.org/mailman/listinfo/python-list
Suggesting a new feature - Inverse Generators
First, a disclaimer. I am a second year Maths and Computer Science undergraduate, and this is my first time ever on Usenet (I guess I'm part of the http generation). On top of that, I have been using Python for a grand total of about a fortnight now. Hence, I apologise if what follows is a stupid suggestion, or if its already been made somewhere else, or if this is not the appropriate place to make it, etc. But I did honestly do some background checking through the Python documentation, www.python.org, FAQs, and so forth before making this post. Basically what I'm trying to say here is, please don't flame this post :) Anyway, I have a suggestion to make for a rather radical new feature in Python. Rather than just struggling to explain and justify it straight out, I'll give the background of how I thought up the feature - and how I worked through the ideas I came up with. The example may seem a bit trivial to start, but bear with me, because I think theres at least some possibility the suggestion has merit. I am writing a project in Python atm, and one thing it needs to do is parse a very simple text file to get a list of records. Its a straightforward kind of thing that I (and I'm sure you) have done many times before in many languages. Each bit of interesting data in the file occurs over 3 or 4 lines of text. On top of this there are lines of random uninteresting junk as well. I decided to write a generator to filter out the junk lines, strip excess whitespace and the like (generators are one of my favourite features in Python). So the main body of code looks like this: def filterJunk(lines): for line in lines: # Do filtering cleaning up stuff on line. # ... yield line def getData(filename): recordList = [] input = file(filename) lines = line.readlines() input.close() for line in filterJunk(lines): # ... create records and add to recordList So far, so good. Next comes the business of actually creating the records from the lines of interesting text. You can probably see the problem I ran into - I need to look at 3 or 4 lines at a time to create the record. Theres no easy way out of this requirement, because whether the record is contained in 3 or 4 lines is conditional on the value of the second line. But the for loop isn't going to allow me to do that. So I rewrote the for loop above as: while True: try: # do stuff repeatedly with lines.next() to add to recordList[] except StopIteration: pass This works. (And yes, there are also a multitude of other reasonably simple ways to approach this problem, some of which I've used in this past. And probably some fancy ways involving map and reduce as well.) But it seems ugly to me somehow. And I'm suspicious of anything that hints of ugliness (in Computer Science, anyway.) I suppose that Python's getting me into the habit of assuming theres always an elegant looking solution. I tried, and failed, to think of some sort of Generator-based concept (I really do love generators! So simple, but so useful!) that would allow me to retain a for loop. I guess that, essentially, I feel this task is really just iterating over the lines, and that iterating over something in Python is a job for a for loop. Generators allow you to use for loops all regular iteration. So I wanted to have something vaugely Generator like, that would allow me to get back to using a for loop. It occured to me - what if I had some sort of inverse generator - a function with a resumable call mechanism that retained state, but that would resume when accepting input rather than returning output. For want of a better term, call it an Acceptor. If you think of a Generator as a method acting as (an abstraction of) a source of sequential data, then the Acceptor correspondingly is a sink. I started playing round with the Acceptor idea, thinking about how it might work. I imagined a simple mirroring of Generator syntax - using a new keyword, accept, to take in a value, just as Generator's use yield to return a value. Here's my first attempt at 'coding' my precious for loop using an imaginary Acceptor: def combineIntoRecord(): # This is an acceptor function optionalline = None # We may not get given a value for this line accept firstline accept secondline if condition(secondline): accept optionalline accept lastline r = createRecord(firstline, secondline, lastline, optionalline) return r recordlist = [] for line in lines: recordlist.append(combineIntoRecord(line)) I've since thought about it somewhat, and its clear I got this first try just plain wrong. Its got a number of hideous defects. First, combineIntoRecord() is 'accepting' its values by taking a magical argument, line, that does not appear in the argument list. Second, in this particular syntax, do combineIntoRecord(x)at line 50 and combineIntoRecord(y)at line 200 want x and y to be
Re: Suggesting a new feature - Inverse Generators
Sorry about the mangled formatting... like i said, first time on Usenet Suggestions, comments, replies, etc most welcome. This definitely includes replies of the form: This is stupid, because... provided it isnt followed with youre a jerk who knows nothing. Period. Heres a follow up rant in the form of a QA, trying to answer what I think are likely or interesting questions: Q: Is this idea even remotely feasible to actually implement? A: No Idea Q: Are you volunteering to implement it? A: Not really. I'd have no clue where to start. I probably don't even have enough C experience to begin to understand the Python source. But if some real Python dev (or devs)actually wants to implement this, and is willing to humour an undergraduate by somehow utilising assistance in form a very limited set of programming skills, well, then I'd be highly flattered and more than happy to help :) Q: The whole document is full of half-formed ideas, hundredth-formed ideas, mistakes(conceptual/typograhpcial/stylistic/grammatical/terminological/programming/...), inconsistencies, random nonsense.. A: Firstly, thats not a question, its a statment. Secondly, see the very first paragraph. Thirdly, the whole document, from initial attempts to code the original for loop (yes, it is a real program I'm trying to write here), to thinking of Acceptors, refining the model to something vaguely coherent, coming up with examples, and typing it all out, was produced on the fly, in the space of 5 hours or so. I attempted to give it a semblance of coherent structure at first, but soon gave up. Its basically stream of conciousness production. The bit where the first, nonsensical example is given, is literally where I first tried to forumlate the idea in code, saw the massive holes, stopped, thought about it for a few minutes, and came backed and typed out the much improved second version. The whole thing is totally unedited.Oh, and I had virtually no sleep last night. A real answer, with respect to the issue of terminology: If I use technical terms loosely, e.g., if I improperly use 'method' for 'function' or vice versa (a hang up from dealing with languages that only have one e.g. Java, or the other, e.g. C) , please forgive me. I hope what I'm trying to say is still clear enough. And as for coding style, Python itself is inconsistent (or to be more diplomatic, not obsessively concerned with the relatively minor issue of) using underscore_seperated_words or mixedCaseInstead, etc. And again, I cry the nefarious influence of Java Q: Did you steal this from somewhere else? A: No, its entirely something I thought of, by myself, in the last 5 hours. Thats not to say something like it (or more likely, better than it) hasnt been thought of somewhere else by someone else. But if it has, I havent seen it. To give credit where due though: I was motivated by the various examples, from sources like www.python.org, of how Generators can be used to do things really elegantly. Also, I'm still tossing around ideas in the back of my mind from a great talk given at my university by Rob Pike, of Google, about a language he helped devise and implement called sawzall (or something close). Its used to do processing with Google's massive data sets and highly parallel computing architecture, yet its incredibly simple to understand and very efficient. I guess it was only tenuously related to the idea presented here. But it was certainly very inspiring in a general computer-science-enthusiasm kind of way. Q: Why did you go to all this trouble thinking up this feature when you could have solved the original problem in so many other, simpler ways? A: I honestly can't give a decent justification :-) Whenever I've needed to do things like: line = readline from file if (line is some sort of 'extra' data) do something with line line = readline from file # get the 'regular' data ... in the past, in Pascal, Java and the like, it always irked me. Don't ask why, it just did. I thought I could get around it with generator in Python, but I couldnt. In trying to think of a generator solution, I more or less randomly thought of extending the generator concept somehow, and I decided to see where it took me. I thought it took me to somewhere interesting, and possibly worthy of further investigation. Q: What about using some sort of 'sequential data sink' that doesn't use 'pretending to be a function' syntax, e.g. a simple Class of some sort? A: Maybe. You can have Iterators without Generators. Maybe you can have inverse Iterators without inverse Generators, I havent thought about it. I love the 'pretending to be a function' syntax, its part of what makes Generators so elegant. So I tried to emulate it. Q: What could be some of the benefits of introducing this feature? What could it be used for? A: Again, I don't really know. Past the examples I've given, I havent really thought about possible
Re: Grouping code by indentation - feature or ******?
Python's way of grouping is VERY good. Over the last 30+ years I've seen a lot of code (good and bad) in many languages. IMHO good code (independent of language) always uses indentation, even when other block constructs (like braces) is available. Python developers thought that this was redundant. Just make the indentation mean something and lose the block construct characters. Secondly, Python nudges me into writing better (easier to maintain and clearer to understand) code by influencing me towards splitting my code into smaller functions/classes. If I find myself with more than 3-4 levels of indentation, I probably need to move some of the lower level code into a function or a class anyway (I actually ran into this this very morning). Some might interpret this as a negative, I don't. I find that a lot of programmers put WAY too much code into single individual modules (main programs, functions) for their own good. It is harder to read, harder to understand, and harder to maintain. I believe that Python tends to make these programmers better by influencing them to write more modular code. The best method for deeply nested grouping is usually the introduction of functions/classes that divide the deeply nested grouping into more manageable and debuggable pieces. Larry Bates Tim Tyler wrote: What do you guys think about Python's grouping of code via indentation? Is it good - perhaps because it saves space and eliminates keypresses? Or is it bad - perhaps because it makes program flow dependent on invisible, and unpronouncable characters - and results in more manual alignment issues by preventing code formatters from managing indentation? Python is certainly pretty unorthodox in this area. How would you have dealt with the issue of how to group statements? -- http://mail.python.org/mailman/listinfo/python-list
Re: Suggesting a new feature - Inverse Generators
Jordan Rastrick [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] def combineIntoRecord(): # This is an acceptor function optionalline = None # We may not get given a value for this line accept firstline accept secondline if condition(secondline): accept optionalline accept lastline r = createRecord(firstline, secondline, lastline, optionalline) return r recordlist = [] for line in lines: recordlist.append(combineIntoRecord(line)) How about doing it this way? class Acceptor: def __init__(self, gen): self.gen = gen def next(self): firstline = self.gen.next() secondline = self.gen.next() if condition(secondline): optionalline = self.gen.next() accept lastline r = createRecord(firstline, secondline, lastline, optinalline) return r This is just a generator done longhand. If anything in Acceptor.next raises StopIteration, so will Acceptor.next itself. Which means that you can now write this: for r in Acceptor(line): recordlist.append(r) or, for that matter, recordlist = list(Acceptor(line)) Incidentally, I did not try to fix the bug in your code that if condition(secondline) is false, optionalline never gets set so the program will crash :-) -- http://mail.python.org/mailman/listinfo/python-list
Re: Version Number Comparison Function
I can't assume there are the same number of '.'s or there are the same number of digits per version. I don't know how the tuple comparison works offhand. But that seems like it would work if you split it. The suggestion with the re module seems generic enough and looks like it will work as is. Thanks. -- http://mail.python.org/mailman/listinfo/python-list
(no subject)
#! rnews 1995 Newsgroups: comp.lang.python Path: news.xs4all.nl!newsspool.news.xs4all.nl!transit.news.xs4all.nl!news-spur1.maxwell.syr.edu!news.maxwell.syr.edu!nntp.abs.net!attws2!ip.att.net!NetNews1!xyzzy!nntp From: Jeff Sandys [EMAIL PROTECTED] Subject: Re: Python for a 10-14 years old? X-Nntp-Posting-Host: e515855.nw.nos.boeing.com Content-Type: text/plain; charset=us-ascii Message-ID: [EMAIL PROTECTED] Sender: [EMAIL PROTECTED] (Boeing NNTP News Access) Content-Transfer-Encoding: 7bit Organization: juno X-Accept-Language: en References: [EMAIL PROTECTED] Mime-Version: 1.0 Date: Fri, 25 Mar 2005 16:09:50 GMT X-Mailer: Mozilla 4.79 [en]C-CCK-MCD Boeing Kit (Windows NT 5.0; U) Xref: news.xs4all.nl comp.lang.python:369133 Lines: 35 How to Think Like a Computer Scientist is a great book for this age group. It is easy to read, in nice easy to digest steps, with enough examples. I will be using this book for a Middle School (7-8 grade, 12-14 year old) Python Programming Club. The hard part is guiding students into rewarding projects that can be accomplished in a short time. John Zelle's _Python Programming: An Introduction to Computer Science_ is also a very good, but it is aimed at high school and first year college students. Another thing that might be useful is if she has a friend that is interested in learning programming. They can pair program with one reading the book while the other drives the computer. Learning is faster and more fun with pair programming. Check out the Python Edu-SIG: http://www.python.org/sigs/edu-sig/ [EMAIL PROTECTED] wrote: ... The only tutorial I have found so far is How to Think Like a Computer Scientist - Learning with Python which, while very good indeed, is geared towards adult newbie students. Is there something out there like Python for kids which would explain *basic* programming concepts in a way which is accessible and entertaining for kids aged 10-14 (that about where her brain is right now) and which would allow them to play around and have fun solving small problems? Many thanks in advance, TN -- http://mail.python.org/mailman/listinfo/python-list
Re: Suggesting a new feature - Inverse Generators
Jordan Rastrick wrote: [CHOP] Behold: # An Acceptor/Generator!!! def combineIntoRecords(): optionalline = None # We may not get given a value for this line accept firstline accept secondline if condition(secondline): accept optionalline accept lastline yield createRecord(firstline, secondline, optionalline, lastline) That's a nice example, but why not: def combineIntoRecords(iterable): iterator = iter(iterable) optionalline = None firstline = iterator.next() secondline = iterator.next() if condition(secondline): optionalline = iterator.next() lastline = iterator.next() yield createRecord(firstline, secondline, optionalline, lastline) ??? -tim def getData(lines): return list(combineIntoRecords(filterJunk(lines))) So, alas, my beloved for loop was not saved after all. Fortunately, the dreaded While loop has been vanquished. In fact all loopiness has disappeared. Along with any other semblance of a main method. I think I like the finished result. I'll leave if for you to decide if you like it too. -- http://mail.python.org/mailman/listinfo/python-list
Re: Version Number Comparison Function
On 25 Mar 2005 07:34:38 -0800, Keith [EMAIL PROTECTED] wrote: Is there a function for comparing version numbers? E.g. 0.1.0 0.1.2 1.876b 1.876c 3.2.2 3.4 How about a simple string comparison? Python 2.3.3 (#1, Mar 9 2004, 14:21:31) [GCC 3.3 20030304 (Apple Computer, Inc. build 1493)] on darwin Type help, copyright, credits or license for more information. '0.1.0' '0.1.2' True '1.876b' '1.876c' True '3.2.2' '3.4' True Beyond that, there seems to be sufficient variation between version number schemes, and something interesting often happens immediately before the final version (e.g. 1.0rc4 becomes 1.0), that you may have to know something more about where you particular version numbers come from. Regards, Dan -- Dan Sommers http://www.tombstonezero.net/dan/ c = 1 -- http://mail.python.org/mailman/listinfo/python-list
Re: Grouping code by indentation - feature or ******?
Hi All-- Larry Bates wrote: Secondly, Python nudges me into writing better (easier to maintain and clearer to understand) code by influencing me towards splitting my code into smaller functions/classes. If I find myself with more than 3-4 levels of indentation, I probably need to move some of the lower level code into a function or a class anyway (I actually ran into this this very morning). Some might interpret this as a negative, I don't. I find that a lot of programmers put WAY too much code into single individual modules (main programs, functions) for their own good. Agreed. Any method where you have to scroll to figure out what matches what is _too big_. This principle holds true for any language. Keeping to that aesthetic forces you to modularize your code and often generates far more flexible functions/methods than you would have any right to expect otherwise. As far as grouping by indentation goes, it's why I fell in love with Python in the first place. Braces and so on are just extraneous cruft as far as I'm concerned. It's the difference between Vietnamese verbs and Latin verbs;-) Metta, Ivan -- Ivan Van Laningham God N Locomotive Works http://www.andi-holmes.com/ http://www.foretec.com/python/workshops/1998-11/proceedings.html Army Signal Corps: Cu Chi, Class of '70 Author: Teach Yourself Python in 24 Hours -- http://mail.python.org/mailman/listinfo/python-list
Re: Suggesting a new feature - Inverse Generators
Thanks for the very fast feedback :) I specifically set optionalline = None to deal with that bug you mentioned, with the implicit assumption createRecord knows how to deal with a None argument. If that guard got destroyed in the copy paste process, my bad. As for you solution, yes, you could do it that way. But I'm not so much interested in alternate solutions to the problem itself, which is to be honest trivial. I'm intereseted in the implications of the imaginary solution of the Acceptor function. Just as you can have Iterators (an abstract class based solution to iteration) without Generators, yet Generators are still of interest, so you could solve this problem without Acceptors, yet Acceptors are (potentially) of interest. Basically, an Acceptor is linked to a Generator (or some other sequence) in the way you have linked the class implementation to a Generator. So this is a kind of implementation of an Acceptor using a class. I like the Acceptor syntax, though. And I'm wondering if maybe there are more complex examples that are harder or impossible to do your way... I think I already put something (briefer) in the QA bit along these lines -- http://mail.python.org/mailman/listinfo/python-list
Re: Suggesting a new feature - Inverse Generators
Tim Hochberg wrote: Jordan Rastrick wrote: itertools.groupby enables you to do this, you just need to define a suitable grouping function, that stores its state: For example, if short lines should be appended to the previous line: from itertools import groupby linesource = \ Here is a long line, long line, long line and this is short and this is short Here is a long line, long line, long line and this is short.splitlines() def record(item, seq = [0]): if len(item) 20: seq[0] +=1 return seq[0] for groupnum, lines in groupby(linesource, record): ... print .join(lines) ... Here is a long line, long line, long lineand this is shortand this is short Here is a long line, long line, long lineand this is short Michael -- http://mail.python.org/mailman/listinfo/python-list
Re: Distributing closed source modules
Fuzzyman wrote: Dave Brueck wrote: It's certainly something lot's of people are interested in. I guess it depends who your audience is. If ytour code isn't for *mass* distribution - the chances of people putting a lot of effort into breaking it are greatly reduced. I don't htink it's necessarily futile. By futile I meant that, if the code ends up running on a user's machine, then a sufficiently motivated person could crack it wide open, regardless of implementation language - the only way to truly protect the code is to never let it out of your hands (i.e. it's accessible just via a web service). -Dave -- http://mail.python.org/mailman/listinfo/python-list
Re: Suggesting a new feature - Inverse Generators
Yes, granted. This is basically the same as Andrew's reply, except with Iterators in place of generators, so I'll let my answer to that stand. In fact, its my solution, but with iter.next() in place of accept :) This is probably something like how I wanted to solve the problem when I first was looking at it and wanting a generator based solution. I ended up thinking of this whole Acceptor business as part of getting me to this point. I'll try to reduce my pages of ranting to a single question. In posting, i was wondering if the syntactic sugar (Acceptors) that i invented to implement the solution is of any general interest. So are there maybe examples less straightforward than this one, where Acceptors work better? Or can you always just turn the generator inside out in the way you have done here? If you can always do it your way, well, thats a powerful design pattern, and it just goes to show my faith in Generators was justified :) And that I wasnt thinking hard /clearly enough about how to use them. There are other issues, like Does the Acceptor syntax, although perhaps functionally equivalent to other methods, ever make the code more readable, easier to parse, etc? But they're a lot less important i'd say. -- http://mail.python.org/mailman/listinfo/python-list
Re: Anonymus functions revisited : tuple actions
On 24 Mar 2005 22:16:10 -0800, Kay Schluehr [EMAIL PROTECTED]
wrote:
It's all developed during this discussion. Sometimes I'm a bit
surprised were it goes.
I enjoy exploring ideas this way. Many times it leads to dead ends or
you just end up with a long way back to where you started, but
sometimes you get a surprise, and almost always a deeper understanding
of the subject. :)
To make my intention clear for another time, also for George who
mistrusts these exercises alltogether. I want to derive a syntax and
semantics for anonymus functions ( called tuple-actions ) that are
generalizations of rules that are already used implicitely within
Python e.g. tuple-unpacking. This is done by progressive interpretation
and extension. They are not there by means of an accident, what Guido
claims about the current lambda which he feels to be sticked onto the
language.
Looking at the syntax of lambda, I think I agree with Guido.
result = lambda *args: expression
It's works like a function, but is formatted like a for or if
statement. It should have been something like this.
result = lambda{ *args: expression}
Another interesting possibility by exploring ideas and concepts. :)
Using a dictionary instead of ()'s to pass the arguments and
expressions. This would simplify parsing it, because it could be
handled as an an object instead of having to parse the args and
expression first.
What if you could:
x = lambda{ x, y: x+y}
Hmm comma creates a problem here. so...
x = lambda{ (x,y): x+Y }
This is more consistent with python syntax and makes more since. the
args are in a tuple as they would be in function.
x = lambda{ (x,y): x+y } is same as x = function(x,y): return x+y
Could this work too?:
x, y, z = lambda{ (x,y): x+y, (x,z):x+z, (x,v):x+v }
Short hand for:
x,y,z = lambda{(x,y):x+y}, lambda{(x,z):x+z, lambda{(x,v):x+v}
For compatibility purposes, You would need to give it a different
name:
af, afn, ann, lamb, lam, lm, ?
Or just call it what it is.. function{(args):expression}
Then it would be easy to explain, teach, and remember.
Ron_Adam
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Re: Version Number Comparison Function
[Pardon the piggybacking. My news-server does not see the OP's message.] Fredrik Lundh wrote: Keith wrote: Is there a function for comparing version numbers? E.g. 0.1.0 0.1.2 1.876b 1.876c 3.2.2 3.4 distutils has a set of version classes with comparisons. In [1]:from distutils import version In [2]:version? Type: module Base Class: type 'module' String Form:module 'distutils.version' from '/System/Library/Frameworks/Python.framework/Versions/2.3/lib/python2.3/distutils/version.pyc' Namespace: Interactive File: /System/Library/Frameworks/Python.framework/Versions/2.3/lib/python2.3/distutils/version.py Docstring: Provides classes to represent module version numbers (one class for each style of version numbering). There are currently two such classes implemented: StrictVersion and LooseVersion. Every version number class implements the following interface: * the 'parse' method takes a string and parses it to some internal representation; if the string is an invalid version number, 'parse' raises a ValueError exception * the class constructor takes an optional string argument which, if supplied, is passed to 'parse' * __str__ reconstructs the string that was passed to 'parse' (or an equivalent string -- ie. one that will generate an equivalent version number instance) * __repr__ generates Python code to recreate the version number instance * __cmp__ compares the current instance with either another instance of the same class or a string (which will be parsed to an instance of the same class, thus must follow the same rules) -- Robert Kern [EMAIL PROTECTED] In the fields of hell where the grass grows high Are the graves of dreams allowed to die. -- Richard Harter -- http://mail.python.org/mailman/listinfo/python-list
Re: Version Number Comparison Function
On Mar 26, 2005, at 3:34 AM, Keith wrote:
Is there a function for comparing version numbers?
E.g.
0.1.0 0.1.2
1.876b 1.876c
3.2.2 3.4
FWIW,
from distutils import version
version_list = 3.4 3.2.2 1.867c 1.867b 0.1.2 0.1.0.split()
version_list = map(version.LooseVersion, version_list)
version_list.sort()
print version_list
[LooseVersion ('0.1.0'), LooseVersion ('0.1.2'), LooseVersion
('1.867b'), LooseVersion ('1.867c'), LooseVersion ('3.2.2'),
LooseVersion ('3.4')]
print ' '.join(map(str, version_list))
0.1.0 0.1.2 1.867b 1.867c 3.2.2 3.4
It should be noted that distutils.version provides a StrictVersion
class that offers less flexible but more predictable ordering -- see
the module docstrings for more details.
Regards,
Mark Rowe
http://bdash.net.nz/
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Re: Version Number Comparison Function
distutils is one of the places I looked: http://www.python.org/doc/2.3.5/lib/module-distutils.html But I didn't see the functions documented. I am new to Python so I didn't know where else to look. Using distutils seems like it would be the most generic and supported way to compare version numbers. -- http://mail.python.org/mailman/listinfo/python-list
Re: Python docs [was: function with a state]
[EMAIL PROTECTED] wrote: The Python doc, though relatively incompetent, but the author have Really, how could those morons even dream of creating a language, and even writing docs to accompany it?? tried the best. This is in contrast to documentations in unix related things (unix tools, perl, apache, and so on etc), where the writers have absolutely no sense of clear writing, and in most cases don't give a damn and delight in drivel thinking of it as literary. Well, man-pages are at least coherent and precise. It's not literature, it's technical documentation! I think that this is an excellent description of your own writing. :) To be sure, he's a stupid troll, but I think you shouldn't insult him for being bad at English. I bet you (or most Western people anyway) have trouble getting fluent in an Asian language. Imagine the lingua franca were Chinese, non English... -- http://mail.python.org/mailman/listinfo/python-list
Re: Python 2.4 | 7.3 The for statement
On 24 Mar 2005 19:49:38 -0800, brainsucker [EMAIL PROTECTED] wrote: foo = 0 for item1 in range(10) until foo == 2: for item2 in range(10) until foo == 2: foo = item1 + item2 if foo == 2: print Let's see print foo In this case, I'll use the following: try: for item1 in range(10): for item2 in range(10): if item1 + item2 == 2: print Let's see raise StopIteration except StopIteration: pass print item1 + item2 And I tell you what. Actually I'm very lousy remembering things, and if I want the loop to stop in a different number, I'll have to change the code in TWO places. In mine, just one (and this in your codes get worse with more for levels). Another approach: def bar(): for item1 in range(10): for item2 in range(10): if item1 + item2 == 2: print Let's see return item1 + item2 foo = bar() print foo .Facundo Blog: http://www.taniquetil.com.ar/plog/ PyAr: http://pyar.decode.com.ar/ -- http://mail.python.org/mailman/listinfo/python-list
Re: Minidom output of XML escaped characters
Thanks effbot. I haven't had much use for XML comments so far and I guess other people haven't either because it seems they are hardly ever mentioned. http://groups-beta.google.com/groups?hl=enlr=c2coff=1q=xml+comment+pythonqt_s=Search+Groups -- http://mail.python.org/mailman/listinfo/python-list
Re: Grouping code by indentation - feature or ******?
Antoon Pardon wrote: I have problems with all languages currently available, so I use those which rub me wrong the least. ... [I]t doesn't weight heavy enough to go and use an other language, although I keeping looking at the other languages. I think the operational definition of a zealot is someone who thinks what they have is absolutely perfect, and refuses to examine the alternatives. Not a very inspiring slogan though: Python - the least of 1,000+ evils. -- http://mail.python.org/mailman/listinfo/python-list
Re: Anonymus functions revisited : tuple actions
Ron_Adam wrote:
What if you could:
x = lambda{ x, y: x+y}
Hmm comma creates a problem here. so...
from __future__ import braces
SyntaxError: not a chance
Reinhold ;)
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Re: Anonymus functions revisited
On 25 Mar 2005 10:09:50 GMT, Duncan Booth
[EMAIL PROTECTED] wrote:
I've never found any need for an is_defined function. If in doubt I just
make sure and initialise all variables to a suitable value before use.
However, I'll assume you have a good use case.
I admit that that is the better practice. George's example was the
conversion of data from one form to another where the data is mixed
with complete and incomplete items. And Kay is looking at tuple
unpacking.
It's hard to beat try/except for these situations though. :)
I cleaned it up some more and figured out the proper use of
_getframe(). So no lambdas, and no passing of locals needed., and it
checks for globals and builtins before defining the default value so
as not to over write a readable value.
I'm not sure what the best behavior should be. Maybe a routine to
tell where a name is, ie.. local, global, builtin, or a writable
global? maybe isa() return the location or None.? I think that would
be better.
The best purpose for utilities like these is for debugging and getting
feedback about the environment. So I'm thinking of putting them in a
module for that purpose. I have a subroutine to list all the names
attached to an object. I think I can add that a bit now too.
#---Here's the code-
import sys
def isa(v):
Check if a varable exists in the current
(parent to this function), global, or
builtin name spaces.
use: bool = isa( str )
returns True or False
plocals = sys._getframe(1).f_locals
if plocals.has_key(v) or globals().has_key(v) or \
__builtins__.locals().has_key(v):
return True
return False
def ifno(v, obj=None):
Check if a varable does not exists, return a
default value, otherwise return the varable obj.
use: obj = ifno( str [,obj=None] )
if str exist, returns str's object
if str does not exist, returns specified object
plocals = sys._getframe(1).f_locals
if plocals.has_key(v):
return plocals[v]
if globals().has_key(v):
return globals()[v]
if __builtins__.locals().has_key(v):
return __builtins__.locals()[v]
return obj
def test():
Test isa() and ifno() functions:
# Totally useless routine. ;)
import random
for n in range(25):
# Delete a random x,y,z coordinate to
# simulate an unrealiabe data source.
d = random.choice([1,2,3])
if d==1:
if isa('x'): del x
elif d==2:
if isa('y'): del y
else:
if isa('z'): del z
# Replace the missing Varible with a random number.
r = int(random.random()*100)
x, y, z = ifno('x',r), ifno('y',r), ifno('z',r)
print x, y, z
if __name__ == '__main__':
test()
#-
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Re: Version Number Comparison Function
I recently saw this: http://www.egenix.com/files/python/mxTools.html mx.Tools.verscmp(a,b) Compares two version strings and returns a cmp() function compatible value (,==, 0). The function is useful for sorting lists containing version strings. The logic used is as follows: the strings are compared at each level, empty levels defaulting to '0', numbers with attached strings (e.g. '1a1') compare less than numbers without attachement (e.g. '1a1' '1). Keith wrote: Is there a function for comparing version numbers? E.g. 0.1.0 0.1.2 1.876b 1.876c 3.2.2 3.4 Keith -- http://mail.python.org/mailman/listinfo/python-list
mod_python, user missing
apache conf Directory /python-publisher/ SetHandler mod_python PythonHandler mod_python.publisher /Directory and this is in /python-publisher/index.py __auth_realm__ = 'VIP' def __auth__(req, user, passwd): if user == 'noppa' and passwd == 'potti': return True else: return False def __access__(req, user): if user == 'noppa': return True else: return False def index(req): req.get_basic_auth_pw() user = req.user return 'user is %s' % (user) So problem is, how I get user in index function? That gives allways None -- (8) -- http://mail.python.org/mailman/listinfo/python-list
Re: Suggesting a new feature - Inverse Generators
I'll try to reduce my pages of ranting to a single question. In posting, i was wondering if the syntactic sugar (Acceptors) that i invented to implement the solution is of any general interest. So are there maybe examples less straightforward than this one, where Acceptors work better? Or can you always just turn the generator inside out in the way you have done here? If you can always do it your way, well, thats a powerful design pattern, and it just goes to show my faith in Generators was justified :) And that I wasnt thinking hard /clearly enough about how to use them. There are other issues, like Does the Acceptor syntax, although perhaps functionally equivalent to other methods, ever make the code more readable, easier to parse, etc? But they're a lot less important i'd say. To me your acceptors look like micro-threads or similar concepts that have been popped up here every now and then - but so far it seems they didn't end up beeing included. I can't say for what reasons though. Just yesterday I looked into stackless python to grasp what it does, and while it is not syntactically different to standard python, it seems to make coding the way you intend to do possible. -- Regards, Diez B. Roggisch -- http://mail.python.org/mailman/listinfo/python-list
Suggest more finesse, please. I/O and sequences.
Would you like to suggest me any improvements for the following code?
I want to make my implementation as simple, as Python - native, as fine as
possible.
I've written simple code, which reads input text file and creates words'
ranking by number of appearence.
Code:
---
import sys
def moreCommonWord( x, y ):
if x[1] != y[1]:
return cmp( x[1], y[1] ) * -1
return cmp( x[0], y[0] )
wordsDic = {}
inFile = open( sys.argv[1] )
for word in inFile.read().split():
if wordsDic.has_key( word ):
wordsDic[word] = wordsDic[word] + 1
else:
wordsDic[word] = 1
inFile.close()
wordsLst = wordsDic.items()
wordsLst.sort( moreCommonWord )
outFile = open( sys.argv[2], 'w')
for pair in wordsLst:
outFile.write( str( pair[1] ).rjust( 7 ) + : + str( pair[0] ) +
\n )
outFile.close()
---
In particular, I don't like reading whole file just to split it.
It is easy to read by lines - may I read by words with that ease?
PS I've been learning Python since todays morning, so be understanding :
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Greets,
Piotrek
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Re: Suggesting a new feature - Inverse Generators
Wow, if I'm going to get replies (with implemented solutions!) this quickly, I'll post here more often :-) This is the most different to my solution, and also the shortest, and therefore the most interesting, reply so far. Its also the last one I'll reply to before I go to bed. Its taken me a while to get a rough understanding of this code, but I think I have some idea. Correct me if I'm wrong. groupby groups based on value of line(record) Record returns 1 for the first line, 1 of the second, 1 for the 3rd, then 2 for the 4th because seq[0] gets incremented since len(line) 20 OK thats fair enough. But how does record retain state between calls? How is that related to the fact your storing your value as a singleton list, instead just an int? It seems a little confusing to be honest, probably mainly due to my unfamiliarity with groupby. Retaining state between method calls is part of what interests me so much about the Generator/ Acceptor case. Here youre retaining state between calls with none of the special syntax used for example in Generators. How? Is it a side effect of the way groupby uses record? If so, then thats a littleoblique and unreadable for my liking. Is the state the record returns passed back to it somehow? I take it gets passed a value for seq at some point, seeing as how you've bothered to define it as a default argument rather than just seq = [0] on the first line. That works, but at the cost of having to return and pass all of state every call. I imagine other solutions (Generator/Acceptor based etc) would be substanitally more efficient. And again more readable, to a Python beginner such as myself at least. Still, this is fascinating going to have to spend some time experimenting with groupby as soon as I get a chance -- http://mail.python.org/mailman/listinfo/python-list
Re: Python 2.4 | 7.3 The for statement
-- Your code foo = 0 for item1 in range(10): for item2 in range(10): foo = item1 + item2 if foo == 2: print Let's see break # let's go if (item1 + item2) == 2: break # one more time print foo The outer loop never reaches 1, so we can get rid of it along with the second if statement, the additions aren't needed either. So what you have left is this. for foo in range(3): pass print Let's see print foo Which is the same as: print let's see\n, foo I know that isn't the point. Just couldn't resist. ;) Ron_Adam -- http://mail.python.org/mailman/listinfo/python-list
Re: Suggesting a new feature - Inverse Generators
Jordan Rastrick wrote: Wow, if I'm going to get replies (with implemented solutions!) this quickly, I'll post here more often :-) That is indeed typical of this most attentive group :-) Its taken me a while to get a rough understanding of this code, but I think I have some idea. It is just an example jotted in 2 min - no doubt it could be made clearer. Correct me if I'm wrong. groupby groups based on value of line(record) No, groupby, groups on the value of record(item), where item is given by iterating over linesource You should check the itertools documentation: http://docs.python.org/lib/itertools-functions.html Record returns 1 for the first line, 1 of the second, 1 for the 3rd, then 2 for the 4th because seq[0] gets incremented since len(line) 20 In this case, it doesn't matter what record returns, as long as it is equal for successive values of item that should be grouped OK thats fair enough. But how does record retain state between calls? How is that related to the fact your storing your value as a singleton list, instead just an int? You are asking about the fundamental behavior of Python: argument passing, mutable objects and scopes. It seems a little confusing to be honest, probably mainly due to my unfamiliarity with groupby. Retaining state between method calls is part of what interests me so much about the Generator/ Acceptor case. Here youre retaining state between calls with none of the special syntax used for example in Generators. How? Is it a side effect of the way groupby uses record? If so, then thats a littleoblique and unreadable for my liking. No, it's nothing special about groupby. record simply stores its state in a mutable default parameter. This isn't general good practice: at least you have to be careful with it. You can see the behavior in the following example: def accumulate(value, accum = []): ... accum.append(value) ... return accum ... accumulate(1) [1] accumulate(2) [1, 2] accumulate(6) [1, 2, 6] ... Still, this is fascinating going to have to spend some time experimenting with groupby as soon as I get a chance Experimenting is good. So is the the documentation: http://docs.python.org/tut/tut.html Michael -- http://mail.python.org/mailman/listinfo/python-list
Re: Grouping code by indentation - feature or ******?
Antoon Pardon [EMAIL PROTECTED] wrote in message 1) It makes it hard to see how many levels are dedented at the end of a suite, and sometime makes it difficult to see where the end of a suite is. If e.g. you are looking at the code spread over two pieces of paper, it is sometimes hard to see whether the suite ends at the end of the first page or not. One can use appropriately indented comment lines instead of closing brackets for this purpose. 2) It makes it hard to introduce some kind of new syntax constructs. I consider this as much a plus as a minus ;-) 3) Sometimes the structure of the algorithm is not the structure of the code as written, people who prefer that the indentation reflects the structure of the algorithm instead of the structure of the code, are forced to indent wrongly. Do you have any simple examples in mind? Terry J. Reedy -- http://mail.python.org/mailman/listinfo/python-list
Re: Grouping code by indentation - feature or ******?
Tim Tyler [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] What do you guys think about Python's grouping of code via indentation? A major plus. I was fanatic about carefully indenting my C code. Is it good - perhaps because it saves space and eliminates keypresses? It eliminates redundancy. Terry J. Reedy -- http://mail.python.org/mailman/listinfo/python-list
Re: Version Number Comparison Function
On Fri, 25 Mar 2005 17:02:31 +0100, Fredrik Lundh [EMAIL PROTECTED] wrote:
Keith wrote:
Is there a function for comparing version numbers?
E.g.
0.1.0 0.1.2
1.876b 1.876c
3.2.2 3.4
the following works for many common cases:
import re
def cmpver(a, b):
def fixup(i):
try:
return int(i)
except ValueError:
return i
a = map(fixup, re.findall(\d+|\w+, a))
b = map(fixup, re.findall(\d+|\w+, b))
return cmp(a, b) # -1 if ab, 0 if a=b, 1 if ab
[OT] Visually, I like the nested def fixup, and I realize
that for cmpver execution overhead is not likely to be an issue,
but in general, what do you think of not being able
to write it that way if MAKE_FUNCTION overhead is unacceptable?
What if we had something like
@sticky('fixup') # evaluate binding only first time
def cmpver(a , b):
def fixup ... ?
Regards,
Bengt Richter
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Re: Suggesting a new feature - Inverse Generators
Michael Spencer wrote: Still, this is fascinating going to have to spend some time experimenting with groupby as soon as I get a chance Experimenting is good. So is the the documentation: http://docs.python.org/tut/tut.html Reading documentation is a good idea, but I think your example would be more clear for Jordan if you used function attributes: def record(item): if len(item) 20: record.seq +=1 return record.seq record.seq = 0 Serge. -- http://mail.python.org/mailman/listinfo/python-list
Re: Suggesting a new feature - Inverse Generators
Terminology: To me and some (most?) others posting here and, I believe, both the docs and the common meaning of 'generator', a Python generator is the particular kind of iterator that produces multiple values on request and which is created by the generator function that you write. Acceptors (consumers): The concept is known to both CS and Python developers. According to Tim Peters, Python generators constitute 'semi-coroutines'. Any full coroutine mechanism (Stackless, for instance) will allow the reverse (not inverse, which would undo rather than complement). For various reasons, the Python developers choose that data chains should be written as consumer code getting data from a generator, which might in turn get data from a generator. In your example, opening and reading the lines of the data file could be done by filterjunk, not the main function, but I can see reasons both ways. For your specific problem, you could, I believe, use an intermediate generator (which could also be combined with filterjunk) that combines lines into complete text records. Something like (ignoring any fussy details left out): def textrecord(file): trlines = [] for line in filterjunk(file): trlines.append(line) if complete(trline): yield ''.join(trlines) # where 'complete' is code to determine if have all lines in record or not Terry J. Reedy -- http://mail.python.org/mailman/listinfo/python-list
Re: Grouping code by indentation - feature or ******?
On Friday 25 March 2005 08:39 am, Ivan Van Laningham wrote: As far as grouping by indentation goes, it's why I fell in love with Python in the first place. Braces and so on are just extraneous cruft as far as I'm concerned. It's the difference between Vietnamese verbs and Latin verbs;-) Say I buy into the indentation ideology. Python then has this inconsistency: : Why do we need : at the end of our if and for loops? I spend approximately 6 minutes/100 lines of code going back and finding all of the times I missed :. Is it for cheating? if False: print : Now, what happened to the whitespace idea here? This code seems very unpythonic. I think : is great for slices and lamda where things go on one line, but to require it to specify the start of a block of code seems a little perlish. -- James Stroud, Ph.D. UCLA-DOE Institute for Genomics and Proteomics Box 951570 Los Angeles, CA 90095 http://www.jamesstroud.com/ -- http://mail.python.org/mailman/listinfo/python-list
Re: Suggesting a new feature - Inverse Generators
On Fri, 25 Mar 2005 08:46:12 -0800, Michael Spencer [EMAIL PROTECTED] wrote: Tim Hochberg wrote: Jordan Rastrick wrote: itertools.groupby enables you to do this, you just need to define a suitable grouping function, that stores its state: For example, if short lines should be appended to the previous line: from itertools import groupby linesource = \ Here is a long line, long line, long line and this is short and this is short Here is a long line, long line, long line and this is short.splitlines() def record(item, seq = [0]): if len(item) 20: seq[0] +=1 return seq[0] for groupnum, lines in groupby(linesource, record): ... print .join(lines) ... Here is a long line, long line, long lineand this is shortand this is short Here is a long line, long line, long lineand this is short Nice, but I think record is a bit opaque semantically. How about group_id or generate_incrementing_unique_id_for_each_group_to_group_by or such? Regards, Bengt Richter -- http://mail.python.org/mailman/listinfo/python-list
Re: Suggesting a new feature - Inverse Generators
Michael Spencer wrote: itertools.groupby enables you to do this, you just need to define a suitable grouping function, that stores its state: Michael, this would make a great Python Cookbook Recipe. --Scott David Daniels [EMAIL PROTECTED] -- http://mail.python.org/mailman/listinfo/python-list
Re: Grouping code by indentation - feature or ******?
James Stroud wrote: On Friday 25 March 2005 08:39 am, Ivan Van Laningham wrote: As far as grouping by indentation goes, it's why I fell in love with Python in the first place. Braces and so on are just extraneous cruft as far as I'm concerned. It's the difference between Vietnamese verbs and Latin verbs;-) Say I buy into the indentation ideology. Python then has this inconsistency: : Why do we need : at the end of our if and for loops? I spend approximately 6 minutes/100 lines of code going back and finding all of the times I missed :. Is it for cheating? if False: print : Now, what happened to the whitespace idea here? This code seems very unpythonic. I think : is great for slices and lamda where things go on one line, but to require it to specify the start of a block of code seems a little perlish. During the usability studies for the language ABC, which Guido worked on before developing Python and also used indentation for grouping, it was found that the colon improved readability. I don't know what those studies said about the frequency of people forgetting to put in the colon. Anecdotally, I can say that I do it very rarely. -- Robert Kern [EMAIL PROTECTED] In the fields of hell where the grass grows high Are the graves of dreams allowed to die. -- Richard Harter -- http://mail.python.org/mailman/listinfo/python-list
Re: Grouping code by indentation - feature or ******?
On Fri, 25 Mar 2005 11:38:37 -0800, Robert Kern [EMAIL PROTECTED] wrote: James Stroud wrote: On Friday 25 March 2005 08:39 am, Ivan Van Laningham wrote: As far as grouping by indentation goes, it's why I fell in love with Python in the first place. Braces and so on are just extraneous cruft as far as I'm concerned. It's the difference between Vietnamese verbs and Latin verbs;-) Say I buy into the indentation ideology. Python then has this inconsistency: : Why do we need : at the end of our if and for loops? I spend approximately 6 minutes/100 lines of code going back and finding all of the times I missed :. Is it for cheating? if False: print : Now, what happened to the whitespace idea here? This code seems very unpythonic. I think : is great for slices and lamda where things go on one line, but to require it to specify the start of a block of code seems a little perlish. During the usability studies for the language ABC, which Guido worked on before developing Python and also used indentation for grouping, it was found that the colon improved readability. I don't know what those studies said about the frequency of people forgetting to put in the colon. Anecdotally, I can say that I do it very rarely. I can't remember having ever done it, although I am sure I have. The real question is, though, 6 minutes per 100 lines of code? There probably aren't more than 30 lines out of those 100 that should end in a colon. Assuming you forget half your colons, you're spending upwards of 20 seconds per colon? If you want, I'll write a script that checks for colons at the end of lines before increased indentation, and asks you if you want to put one there - I could save you 5.8 minutes per 100 lines of code. How's that for a productivity boost? Peace Bill Mill bill.mill at gmail.com -- http://mail.python.org/mailman/listinfo/python-list
Re: Example Code - Named Pipes (Python 2.4 + ctypes on Windows)
Srijit Kumar Bhadra wrote: Hello, Here is an example of Multithreaded Pipe Server and Client using the excellent ctypes library (Windows). Coincidentally, the other day I just used named pipes in for the first time. I recommend using the excellent win32api extension; I believe it is included by deafult in the ActiveState distro. The API calls look fairly similar, but you pass strings instead of c_whatever_p(), they return tuples, and they throw exceptions instead of returning HRESULT h s.t. FAILED(h). The resulting code feels much more Pythonic. For example, my first test looked like this: def testread(self): Read all data currently in pipe. while True: try: (nRead, nAvail, nMessage) = win32pipe.PeekNamedPipe(self.hFile, 0) if nAvail: (hr, data) = win32file.ReadFile(self.hFile, nAvail) return data except pywintypes.error, e: errno = e.args[0] if errno == 109: # other end disconnected self.disconnect() self.connect() else: raise It's kind of cool that you can directly port C code to Python, but the end result is IMO nigh-unreadable. p -- http://mail.python.org/mailman/listinfo/python-list
