date:20041217

Mike Thompson wrote:

 File C:\Python23\Lib\site-packages\elementtree\ElementTree.py, line 709, in 
 _write
   for n in node:
 File C:\Python23\Lib\site-packages\elementtree\ElementTree.py, line 227, in 
 __getitem__
   return self._children[index]

 The exception is triggered in ElementTree but the code is fine. Something 
 about the Wing IDE 
 debuger is causing this exception to be thrown.

note that the code is using a for-loop to process all items in a container 
object.  the
IndexError is supposed to tell the for-loop to stop; having a Python IDE report 
this
as an error is remarkably brain-dead...

(do they stop on StopIteration exceptions too?  or IOError exceptions from 
open?)

/F 



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Re: Why are tuples immutable?

2004-12-17 Thread Antoon Pardon

Op 2004-12-17, Jeff Shannon schreef [EMAIL PROTECTED]:
 Adam DePrince wrote:

And how exactly do you propose to mutate an object without changing its
hash value?


* Create this mutate-able object type.  
* Create two objects that are different with different hash values.
* Mutate one so that it is the same as the other.
* Compare their hash values.  

If the hash values are the same, you lose because you didn't keep your
original promise.

If the hash values are different then you just broke your object because
two objects with the same value must have the same hash value, but yours
are different.
  


 Correct me if I'm wrong, here, but I believe that what you're saying 
 here (and my vague memories of the little bit that I've read about 
 hashes) is that, for a well-behaved hash function, then A == B should 
 imply that hash(A) == hash(B).  (The reverse is *not* true, however -- 
 hash(A) == hash(B) does not necessarily say anything about whether A == B.)

 If that is a correct condition for a well-behaved hash function, then it 
 is indeed impossible to have a well-behaved hash function that can be 
 useful in the face of object mutation.  For something like a list, one 
 can only define a poorly-behaved hash-like function.

You are looking at it in a too limited way. You are not forced to
have an == operator that behaves in standard ways. For instance
you can have objects that are only equal if they are the same
and thus can be unequal even if all components are equal.

Even if 

 To take another approach -- given some function that allows lists to 
 (pretend to be) hashable:

 . key = [1,2]
 . d[key] = 'foo'
 . d[[1,2]]
 
 . key.append(3)
 . d[key]
 ???
 .

 As I understand it, it is impossible for there to be a hash function for 
 which both of these cases can return the same object.

How about:

  hash = id


You also make the fault that because people ask for the possibility of
keys being mutable objects, that they want to mutate those object while 
being a key.

 For most uses of 
 dicts, it is necessary that the first case be valid -- a dict isn't 
 going to be very useful to me if I have to pass around all of the 
 objects used as keys in order to access it. Equality-based hashes are 
 necessary, so the second case must then be disallowed.

But you should be carefull not to limit people to what you think is
usefull.

 But isn't it a bit nonsensical that, without ever rebinding key, one can 
 do something like

 . d[key] = 'foo'
 . frombulate(key)
 . d[key]
 Traceback (most recent call last):
   File interactive input, line 1, in ?
 KeyError: key
 .

It is just as nonsensical that, without ever rebinding an element, one
can unsort a list, or violate the heap invariant of a list.

 In order to maintain the logical consistency that if an object is used 
 as a dict key, that same object should reasonably be expected to 
 retrieve the same value, identity-based hashes are necessary.  As a 
 result, the first option must be disallowed.

Then why don't we disallow lists of mutable objects to be sorted or
to be made into a heap. In fact each time we have a structure that
relies on some invariant among its members we should disallow mutable
members because with mutable members the invariant can be violated
without ever rebinding one of the elements.

 In either case, if it's ever possible for equality to change while 
 identity doesn't, then somewhere along the lines one of the core 
 requirements, the contract if you will, of a dictionary *must* be 
 broken.  And while it may be possible to get away with breaking that 
 contract some of the time (by postulating, for example, that if one 
 mutates a dict key then things will break), this will result in more 
 bugs and more confusion over time.  There is no way for Python to be 
 able to behave consistently in the face of mutable dict keys, therefore 
 (In the face of ambiguity, refuse the temptation to guess.) Python 
 declines the temptation of making it trivial to use mutable objects as 
 dict keys.

As it turns out, python makes no difference in difficulty for making
either mutable or immutable objects usable as dictionary keys. The
only difference is that python only made its standard immutable
types hashable and not its standard mutable objects.

-- 
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Re: Multithreading tkinter question

2004-12-17 Thread Eric Brunel

Oleg Paraschenko wrote:
[snip]
In my case Hello works and Quit doesn't (GUI stays frozen).
Linux, Python 2.3.3, pygtk-0.6.9.
That's not a multithreading issue, but just the way the quit method works. 
Try:
-
import time
from Tkinter import *
root = Tk()
b = Button(root, text='Quit')
b.configure(command=root.quit)
b.pack()
root.mainloop()
time.sleep(2)
-
When you click the Quit button, the GUI stays there until the time.sleep ends. 
root.quit just goes out of the mainloop; it doesn't destroy the widgets. To do 
that, you have to add an explicit root.destroy() after root.mainloop()
--
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Re: Step by step: Compiling extensions with MS Visual C++ Toolkit 2003 - msvccompiler-patch.txt (0/1)

2004-12-17 Thread wjb131

Having done steps 1 to 10, I tried building Numeric-23.6. And got the
following error-msg:

F:\install\Numeric-23.6python setup.py build
running build
running build_py
running build_ext
building '_numpy' extension
D:\Programme\Microsoft Visual C++ Toolkit 2003\bin\cl.exe /c /nologo
/Ox /MD /W3
/GX /DNDEBUG -I/usr/include/atlas -IInclude -IPackages\FFT\Include
-IPackages\R
NG\Include -ID:\Python24\include -ID:\Python24\PC /TcSrc\_numpymodule.c
/Fobuild
\temp.win32-2.4\Release\Src\_numpymodule.obj
_numpymodule.c
d:\Python24\include\pyconfig.h(30) : fatal error C1083: Cannot open
include file
: 'io.h': No such file or directory
error: command 'D:\Programme\Microsoft Visual C++ Toolkit
2003\bin\cl.exe' fai
led with exit status 2

why?
Regards
Wolfgang

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pywhich script - where is that module?

2004-12-17 Thread Keith Dart

Have you ever wondered where your python modules get imported from?
Here is a little script, called pywhich, that will tell you.


--
   \/ \/
   (O O)
-- oOOo~(_)~oOOo
Keith Dart [EMAIL PROTECTED]
public key: ID: F3D288E4 

#!/usr/bin/env python

pywhich modname
Tell which Python module is imported.


import sys

def main(argv):
if len(argv)  2:
print __doc__
return
for modname in argv[1:]:
try:
mod = __import__(modname)
except:
print No module or package by named '%s' found. % modname
else:
print %15s : %s % (modname, mod.__file__)

main(sys.argv)
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Re: Why are tuples immutable?

jfj wrote:
Why can't we __setitem__ for tuples?
It seems from your suggestions here that what you really want is a 
single sequence type, list, instead of two sequence types: tuple and 
list.  Under your design, list would support hash, and it would be up to 
the programmer to make sure not to modify a list when using it as a key 
to a dict.  The important thing to understand is that, while this is not 
an unreasonable design decision, it's not the design decision that's 
been made for Python.

Reading the docs and some of GvR's comments on python-dev, my 
understanding is that, while a single sequence type would have sufficed, 
the belief was that there were two mostly non-overlapping sets of tasks 
that one might want to do with sequences.  One set of tasks dealt with 
small collections of related data which may be of different types which 
are operated on as a group[1] (tuples), while the other set of tasks 
dealt with hold[ing] a varying number of objects all of which have the 
same type and which are operated on one-by-one[1] (lists).

Now, when you use a sequence as a key to a dict, you're operating on the 
sequence as a group, not one-by-one.  Given the above conceptions of 
tuple and list then, it is natural to provide tuple with hash support, 
while leaving it out of list.

Note also that tuples being immutable also falls out of the tuple 
description above too.  If you're operating on the sequence as a group, 
then there's no need for __setitem__; __setitem__ is used to operate on 
a sequence one-by-one.

I understand that you'd like a type that is operated on one-by-one, but 
can also be considered as a group (e.g. is hashable).  Personally, I 
don't have any use for such a type, but perhaps others do.  The right 
solution in this case is not to try to redefine tuple or list, but to 
write a PEP[2] and suggest a new datatype that serves your purposes. 
I'll help you out and provide you with an implementation: =)

class hashablelist(list):
def __hash__(self):
return hash(tuple(self))
Now all you need to do is write the Abstract, Motivation and Rationale, 
and persuade the people on c.l.py and python-dev that this is actually a 
useful addition to the language.

Steve
[1] 
http://www.python.org/doc/faq/general.html#why-are-there-separate-tuple-and-list-data-types
[2] http://www.python.org/peps/pep-0001.html
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Re: lies about OOP

2004-12-17 Thread Alex Stapleton

To canadians there is no outside of hockey games.
Jeff Shannon wrote:
Peter Hansen wrote:
P.S.: I'm only half Danish, but the other half is from
a particularly bloodthirsty line of Canadians.

I thought it was physically impossible for Canadians to be bloodthirsty 
outside of hockey games... ;)

Jeff Shannon
Technician/Programmer
Credit International

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Re: BASIC vs Python

2004-12-17 Thread TZOTZIOY

On Fri, 17 Dec 2004 01:43:56 -0600, rumours say that Mike Meyer
[EMAIL PROTECTED] might have written:

Assembler was better - at least you had recursion with
assembler.

You had recursion with BASIC --what you probably mean is that you had no
stacked parameters (unless you imitated that with using an indexed
array).

90 rem recursion
100 print beautiful colours
110 gosub 100
-- 
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...
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Re: Cool object trick

2004-12-17 Thread Alex Stapleton

Except what if you want to access elements based on user input or something?
you can't do
var = varA
obj = struct(varA = Hello)
print obj.var
and expect it to say Hello to you.
objects contain a __dict__ for a reason :P
 Certainly makes writing 'print obj.spam, obj.spam, obj.eggs, obj.bacon,
 obj.sausages, and, obj.spam' a lot easier ;-)
then why dont you have a breakfast class? if you have this many 
properties associated with the same thing you might as well stick them 
in a class anyway.

[EMAIL PROTECTED] wrote:
I rather like it!  I prefer writing obj.spam to obj[spam]!  I wonder if
there is a technical downside to this use of Python?
P.S.
Certainly makes writing 'print obj.spam, obj.spam, obj.eggs, obj.bacon,
obj.sausages, and, obj.spam' a lot easier ;-)
-Original Message-
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of
Jive
Sent: 17 December 2004 06:29
To: [EMAIL PROTECTED]
Subject: Re: Cool object trick
Kinda cool.
It's occured to me that just about everything Pythonic can be done with
dicts and functions.  Your Obj is just a dict with an alternate syntax.  You
don't have to put quotes around the keys.  But that's cool.
class struct(object):
def __init__(self, **kwargs):
self.__dict__.update(kwargs)
# Indented this way, it looks like a struct:
obj = struct(  saying = Nee
   , something = different
   , spam = eggs
  )
print obj.spam
# Is that really much different from this?
obj2 = { saying : Nee
, something : different
, spam : eggs
   }
print obj2[spam]

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MDaemon Warning - virus found: RETURNED MAIL: DATA FORMAT ERROR

2004-12-17 Thread apetchame


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AttachmentVirus name   Action taken
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**


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from [221.69.228.236]

- The following addresses had permanent fatal errors -
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Python RSS aggregator?

2004-12-17 Thread Erik Max Francis

Back in 2000 I made a news aggregation site (REALpolitik, 
http://www.realpolitik.com/) since I didn't find anything that fit my 
needs.  (REALpolitik is unfortunately made in Perl; it was my last 
significant project before I started using Python for most of my work.) 
 At the time, RSS had not reached the near-universality that it has 
now, so RP itself uses a combination of custom scraping and whatever 
XML-type feeds that were available.

I've checked and all the feeds _I_ care about :-) are available in RSS 
now, so it would make sense to move to an RSS aggregator if it has the 
same features.  I've looked around at some that are available, both in 
Python and not, and haven't found anything that had the feature set I 
want.  One in Python would obviously be a huge benefit.

I'm not looking for anything all that fancy, but there are a combination 
of some seemingly basic features I just can't seem to find in other 
aggregators.  They are:

- one-page display:  It's awkward going back and forth between multiple 
feeds in a hierarchical format, and so it's much nicer if they're all 
presented on one page available for perusal.

- filtering news items:  Preferably for filtering out as well as 
highlighting, and also being able to selectively pass on, say, the first 
item in an RSS feed, since some popular feeds use that slot as an 
advertisement.

- caching news items:  I read news sporadically throughout the day, so 
one feature I really like is the ability to queue up new items over 
time, as distinguished by unique GUID.  For example, if an RSS feed only 
provided one (unique) item at all in its feed and that was updated once 
a day, letting the system run for several days would collect them all, 
each stored uniquely and available.

- recent items:  When you check for news, it only shows you the news 
items in each category that are new since you last caught up (catching 
up is the equivalent of a mark all as read feature).  That way, new 
news accumulates, and it's only news you haven't seen before.

Somewhat surprisingly to me, I can't seem to find an aggregator that 
supports all these features (using Mozilla).  Is it possible it's time 
for another Yet Another-type project?

--
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San Jose, CA, USA  37 20 N 121 53 W  AIM erikmaxfrancis
  If love be good, from whence cometh my woe?
  -- Chaucer
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Re: create lowercase strings in lists - was: (No subject)

Thanks for the help. This is the final script:

#!/usr/bin/env python
import os
import sys
import time
import string
import pexpect
import commands


# Test if the words of list2 elements appear in any order in list1 elements
# disregarding case and parens

# Reference list
list1 = [a b C (D), D A B, A B E]
# Test list
list2 = [A B C D, A B D, A E F, A (E) B, A B, E A B ]

def normalize(text, unwanted = (), table = 
string.maketrans(string.ascii_uppercase,string.ascii_lowercase)):
text.translate(table,unwanted)
return set(text.split())


reflist = [normalize(element) for element in list1]
print reflist

#This is the list of sets to test against


def testmember(element):
is element a member of the reflist, according to the above rules?
testelement = normalize(element)
#brute force comparison until match - depends on small reflist
for el in reflist:
if el.issuperset(testelement):
return True
return False

for element in list2:
print element, testmember(element)


the trouble is it throws up the following error for set:

$ ./test.py
Traceback (most recent call last):
  File ./test.py, line 23, in ?
reflist = [normalize(element) for element in list1]
  File ./test.py, line 20, in normalize
return set(text.split())
NameError: global name 'set' is not defined

when I checked http://docs.python.org/lib/genindex.html#letter-s

it said that
set() (built-in function) 

The python I use is the one that comes with cygwin. Does anybody know if the 
following version of python is incomplete or do I need to call built in 
functions in a different way?
 
$ python
Python 2.3.4 (#1, Jun 13 2004, 11:21:03)
[GCC 3.3.1 (cygming special)] on cygwin
Type help, copyright, credits or license for more information.


Michael Spencer [EMAIL PROTECTED] wrote:

 
 Steve Holden wrote:
  Mark Devine wrote:
  
  Actually what I want is element 'class-map match-all cmap1' from list 
  1 to match 'class-map cmap1 (match-all)' or 'class-map cmap1 mark 
  match-all done' in list 2 but not to match 'class-map cmap1'.
  Each element in both lists have multiple words in them. If all the 
  words of any element of the first list appear in any order within any 
  element of the second list I want a match but if any of the words are 
  missing then there is no match. There are far more elements in list 2 
  than in list 1.
   
  
 sounds like a case for sets...
 
# NB Python 2.4
   ...
# Test if the words of list2 elements appear in any order in list1 
 elements
# disregarding case and parens
   ...
# Reference list
list1 = [a b C (D),
   ...   D A B,
   ...   A B E]
# Test list
list2 = [A B C D, #True
   ...   A B D,  #True
   ...   A E F,  #False
   ...   A (E) B,#True
   ...   A B,   #True
   ...   E A B ]
   ...
def normalize(text, unwanted = ()):
   ... conv = .join(char.lower() for char in text if char not in 
 unwanted)
   ... return set(conv.split())
   ...
reflist = [normalize(element) for element in list1]
print reflist
   ...
 [set(['a', 'c', 'b', 'd']), set(['a', 'b', 'd']), set(['a', 'b', 'e'])]
 
 This is the list of sets to test against
 
 
def testmember(element):
   ... is element a member of the reflist, according to the above 
 rules?
   ... testelement = normalize(element)
   ... #brute force comparison until match - depends on small reflist
   ... for el in reflist:
   ... if el.issuperset(testelement):
   ... return True
   ... return False
   ...
for element in list2:
   ... print element, testmember(element)
   ...
 A B C D True
 A B D True
 A E F False
 A (E) B True
 A B True
 E A B True
   
 
 Michael
 
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Re: Cool object trick

2004-12-17 Thread Alex Stapleton

Steven Bethard wrote:
Alex Stapleton wrote:
you can't do
var = varA
obj = struct(varA = Hello)
print obj.var
and expect it to say Hello to you.

The Bunch object from the PEP can take parameters in the same way that 
dict() and dict.update() can, so this behavior can be supported like:

  b = Bunch({varA:Hello!})
  b.varA
'Hello!'
or
  b = Bunch([(varA, Hello!)])
  b.varA
'Hello!'
Steve
thats nothing like what i described.
you are setting the variable name in your code (b.varA), not generating 
the variable name in a string (var = varA) (dictionary key) at 
run-time and fetching it from the __dict__ like i was attempting to 
describe.

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Re: create lowercase strings in lists - was: (No subject)

Mark Devine wrote:
the trouble is it throws up the following error for set:
$ ./test.py
Traceback (most recent call last):
  File ./test.py, line 23, in ?
reflist = [normalize(element) for element in list1]
  File ./test.py, line 20, in normalize
return set(text.split())
NameError: global name 'set' is not defined
The set type became a builtin in Python 2.4.  I would suggest upgrading, 
but if this is not an option, you can put this at the top of the file, 
and it should get rid of the NameError:

from sets import Set as set
Steve
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Re: create lowercase strings in lists - was: (No subject)

Thanks. This version is the version that comes with cygwin. They must be behind.

Steven Bethard [EMAIL PROTECTED] wrote:

 
 Mark Devine wrote:
  the trouble is it throws up the following error for set:
  
  $ ./test.py
  Traceback (most recent call last):
File ./test.py, line 23, in ?
  reflist = [normalize(element) for element in list1]
File ./test.py, line 20, in normalize
  return set(text.split())
  NameError: global name 'set' is not defined
  
 
 The set type became a builtin in Python 2.4.  I would suggest upgrading, 
 but if this is not an option, you can put this at the top of the file, 
 and it should get rid of the NameError:
 
 from sets import Set as set
 
 Steve
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Re: Cool object trick

Alex Stapleton wrote:
you are setting the variable name in your code (b.varA), not generating 
the variable name in a string (var = varA) (dictionary key) at 
run-time and fetching it from the __dict__ like i was attempting to 
describe.
Ahh.  Well if you just want to get an attribute, I don't see why you 
wouldn't do it the normal way:

 b = Bunch(varA=Hello!)
 getattr(b, varA)
'Hello!'
That's what getattr's for. ;)  No need to go poking around in __dict__.
Steve
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Re: BASIC vs Python

2004-12-17 Thread Peter Hickman

Mike Meyer wrote:
BASIC as implented by Microsoft for the Apple II and the TRS 80 (among
others) is simply the worst programming language I have ever
encountered. Assembler was better - at least you had recursion with
assembler.
Basic has progressed much since you last looked at it, time to update your 
facts. Basic has recursion, it compiles to native code, it has objects, can be 
event driven and everything else you would expect of a language.

Computing changes too fast to allow you to think you know it all. Keep up to 
date granddad.

However what basic doesn't have is a portable language definition.
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Re: create lowercase strings in lists - was: (No subject)

I got the script working. Thanks for all your help everyone. Trouble is its not 
showing the correct results. Here is the script and results:

#!/usr/bin/env python
import os
import sys
import time
import string
import pexpect
import commands
from sets import Set as set


# Test if the words of list2 elements appear in any order in list1 elements
# disregarding case and parens

# Reference list
list1 = [a b C (D), D A B, A B E]
# Test list
list2 = [A B C D, A B D, A E F, A (E) B, A B, E A B ]

def normalize(text, unwanted = (), table = 
string.maketrans(string.ascii_uppercase,string.ascii_lowercase)):
text.translate(table,unwanted)
return set(text.split())

reflist = [normalize(element) for element in list1]
print reflist

#This is the list of sets to test against


def testmember(element):
is element a member of the reflist, according to the above rules?
testelement = normalize(element)
#brute force comparison until match - depends on small reflist
for el in reflist:
if el.issuperset(testelement):
return True
return False

for element in list2:
print element, testmember(element)

Here is the results:

$ ./test.py
[Set(['a', 'C', 'b', '(D)']), Set(['A', 'B', 'D']), Set(['A', 'B', 'E'])]
A B C D False
A B D True
A E F False
A (E) B False
A B True
E A B True

The results should be:

 A B C D True
 A B D True
 A E F False
 A (E) B True
 A B False
 E A B True





Michael Spencer [EMAIL PROTECTED] wrote:

 
 Steve Holden wrote:
  Mark Devine wrote:
  
  Actually what I want is element 'class-map match-all cmap1' from list 
  1 to match 'class-map cmap1 (match-all)' or 'class-map cmap1 mark 
  match-all done' in list 2 but not to match 'class-map cmap1'.
  Each element in both lists have multiple words in them. If all the 
  words of any element of the first list appear in any order within any 
  element of the second list I want a match but if any of the words are 
  missing then there is no match. There are far more elements in list 2 
  than in list 1.
   
  
 sounds like a case for sets...
 
# NB Python 2.4
   ...
# Test if the words of list2 elements appear in any order in list1 
 elements
# disregarding case and parens
   ...
# Reference list
list1 = [a b C (D),
   ...   D A B,
   ...   A B E]
# Test list
list2 = [A B C D, #True
   ...   A B D,  #True
   ...   A E F,  #False
   ...   A (E) B,#True
   ...   A B,   #True
   ...   E A B ]
   ...
def normalize(text, unwanted = ()):
   ... conv = .join(char.lower() for char in text if char not in 
 unwanted)
   ... return set(conv.split())
   ...
reflist = [normalize(element) for element in list1]
print reflist
   ...
 [set(['a', 'c', 'b', 'd']), set(['a', 'b', 'd']), set(['a', 'b', 'e'])]
 
 This is the list of sets to test against
 
 
def testmember(element):
   ... is element a member of the reflist, according to the above 
 rules?
   ... testelement = normalize(element)
   ... #brute force comparison until match - depends on small reflist
   ... for el in reflist:
   ... if el.issuperset(testelement):
   ... return True
   ... return False
   ...
for element in list2:
   ... print element, testmember(element)
   ...
 A B C D True
 A B D True
 A E F False
 A (E) B True
 A B True
 E A B True
   
 
 Michael
 
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Re: Step by step: Compiling extensions with MS Visual C++ Toolkit 2003 - msvccompiler-patch.txt (0/1)

2004-12-17 Thread Fuzzyman

[EMAIL PROTECTED] wrote:
 Having done steps 1 to 10, I tried building Numeric-23.6. And got the
 following error-msg:

 F:\install\Numeric-23.6python setup.py build
 running build
 running build_py
 running build_ext
 building '_numpy' extension
 D:\Programme\Microsoft Visual C++ Toolkit 2003\bin\cl.exe /c /nologo
 /Ox /MD /W3
 /GX /DNDEBUG -I/usr/include/atlas -IInclude -IPackages\FFT\Include
 -IPackages\R
 NG\Include -ID:\Python24\include -ID:\Python24\PC
/TcSrc\_numpymodule.c
 /Fobuild
 \temp.win32-2.4\Release\Src\_numpymodule.obj
 _numpymodule.c
 d:\Python24\include\pyconfig.h(30) : fatal error C1083: Cannot open
 include file
 : 'io.h': No such file or directory
 error: command 'D:\Programme\Microsoft Visual C++ Toolkit
 2003\bin\cl.exe' fai
 led with exit status 2

 why?
 Regards
 Wolfgang

If you look at the instructions on :
http://www.vrplumber.com/programming/mstoolkit/

It mentions that you probably need the .NET 2.0beta runtime and SDK.

Regards,

Fuzzy
http://www.voidspace.org.uk/atlantibots/pythonutils.html

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Re: create lowercase strings in lists - was: (No subject)

If I use:
if el.issubset(testelement):
I get a closer anwser but the brackets cause a problem. They are optional in 
the test list so (D) in the test list is equal to D or (D) in the reference 
list. 



Mark Devine [EMAIL PROTECTED] wrote:

 
 I got the script working. Thanks for all your help everyone. Trouble is its 
 not showing the correct results. Here is the script and results:
 
 #!/usr/bin/env python
 import os
 import sys
 import time
 import string
 import pexpect
 import commands
 from sets import Set as set
 
 
 # Test if the words of list2 elements appear in any order in list1 elements
 # disregarding case and parens
 
 # Reference list
 list1 = [a b C (D), D A B, A B E]
 # Test list
 list2 = [A B C D, A B D, A E F, A (E) B, A B, E A B ]
 
 def normalize(text, unwanted = (), table = 
 string.maketrans(string.ascii_uppercase,string.ascii_lowercase)):
   text.translate(table,unwanted)
   return set(text.split())
 
 reflist = [normalize(element) for element in list1]
 print reflist
 
 #This is the list of sets to test against
 
 
 def testmember(element):
   is element a member of the reflist, according to the above rules?
   testelement = normalize(element)
 #brute force comparison until match - depends on small reflist
   for el in reflist:
   if el.issuperset(testelement):
   return True
   return False
 
 for element in list2:
   print element, testmember(element)
 
 Here is the results:
 
 $ ./test.py
 [Set(['a', 'C', 'b', '(D)']), Set(['A', 'B', 'D']), Set(['A', 'B', 'E'])]
 A B C D False
 A B D True
 A E F False
 A (E) B False
 A B True
 E A B True
 
 The results should be:
 
  A B C D True
  A B D True
  A E F False
  A (E) B True
  A B False
  E A B True
 
 
 
 
 
 Michael Spencer [EMAIL PROTECTED] wrote:
 
  
  Steve Holden wrote:
   Mark Devine wrote:
   
   Actually what I want is element 'class-map match-all cmap1' from list 
   1 to match 'class-map cmap1 (match-all)' or 'class-map cmap1 mark 
   match-all done' in list 2 but not to match 'class-map cmap1'.
   Each element in both lists have multiple words in them. If all the 
   words of any element of the first list appear in any order within any 
   element of the second list I want a match but if any of the words are 
   missing then there is no match. There are far more elements in list 2 
   than in list 1.

   
  sounds like a case for sets...
  
 # NB Python 2.4
...
 # Test if the words of list2 elements appear in any order in list1 
  elements
 # disregarding case and parens
...
 # Reference list
 list1 = [a b C (D),
...   D A B,
...   A B E]
 # Test list
 list2 = [A B C D, #True
...   A B D,  #True
...   A E F,  #False
...   A (E) B,#True
...   A B,   #True
...   E A B ]
...
 def normalize(text, unwanted = ()):
... conv = .join(char.lower() for char in text if char not in 
  unwanted)
... return set(conv.split())
...
 reflist = [normalize(element) for element in list1]
 print reflist
...
  [set(['a', 'c', 'b', 'd']), set(['a', 'b', 'd']), set(['a', 'b', 'e'])]
  
  This is the list of sets to test against
  
  
 def testmember(element):
... is element a member of the reflist, according to the above 
  rules?
... testelement = normalize(element)
... #brute force comparison until match - depends on small reflist
... for el in reflist:
... if el.issuperset(testelement):
... return True
... return False
...
 for element in list2:
... print element, testmember(element)
...
  A B C D True
  A B D True
  A E F False
  A (E) B True
  A B True
  E A B True

  
  Michael
  
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setup.py - just what is it for ?

2004-12-17 Thread Richard Shea

Hi - This is probably quite a stupid question but I've never
understood what setup.py does. I've got a situation at the moment
where I would like to use a script (which someone else has written and
made available) to do CGI on a shared webserver to which I do not have
shell access.

The install instructions say run python setup.py but as far as I'm
aware I cannot do that.

There is only one script involved (except for the setup.py !) and so
I'm probably just going to copy it into my cgi-bin and give it a go
but I'd like to know for future reference just how bad could it be if
I did this ? Are there circumstances where you must use setup.py to
have any hope of the code working ?

BTW here is the setup.py in question ...

from distutils.core import setup

classifiers = \
Development Status :: 5 - Production/Stable
Environment :: Web Environment
Intended Audience :: Developers
License :: OSI Approved :: GNU General Public License (GPL)
Operating System :: OS Independent
Topic :: Internet :: WWW/HTTP
Topic :: Internet :: WWW/HTTP :: Dynamic Content :: CGI
Tools/Libraries

import sys
if sys.version_info  (2, 3):
_setup = setup
def setup(**kwargs):
if kwargs.has_key(classifiers):
del kwargs[classifiers]
_setup(**kwargs)

setup(name=cgi_app,py_modules=[cgi_app],
version=1.3,
maintainer=Anders Pearson,
maintainer_email=[EMAIL PROTECTED],
url = http://thraxil.org/code/cgi_app/;,
license = http://www.gnu.org/licenses/gpl.html;,
platforms = [any],
description = CGI and mod_python MVC application framework,
long_description = framework for building MVC CGI and
mod_python
applications. based on the perl CGI::Application module but
more
pythonic.,
classifiers = filter(None, classifiers.split(\n)))


... I would appreciate any information about this (or any tips on how
to deal with no shell access).

thanks

richard
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Re: create lowercase strings in lists - was: (No subject)

2004-12-17 Thread Peter Otten

Mark Devine wrote:

 I got the script working. Thanks for all your help everyone. Trouble is
 its not showing the correct results. Here is the script and results:

In my book it is not working then.

 def normalize(text, unwanted = (), table =
 string.maketrans(string.ascii_uppercase,string.ascii_lowercase)):
 text.translate(table,unwanted) 

Strings are immutable in Python. Make that

  text = text.translate(table, unwanted)

This line of the script's output could have given you a clue:

 [Set(['a', 'C', 'b', '(D)']), Set(['A', 'B', 'D']), Set(['A', 'B', 'E'])]

(I didn't look any further, so there may be other problems)

Peter

PS: Do us a favour and (a) don't top-post (b) use space not tabs in your
source code (c) remove all text quoted from the parent that is not relevant
to your current problem.
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Re: BASIC vs Python

2004-12-17 Thread Peter Otten

Peter Hickman wrote:

 Mike Meyer wrote:
 BASIC as implented by Microsoft for the Apple II and the TRS 80 (among
 others) is simply the worst programming language I have ever
 encountered. Assembler was better - at least you had recursion with
 assembler.
 
 Basic has progressed much since you last looked at it, time to update your
 facts. Basic has recursion, it compiles to native code, it has objects,
 can be event driven and everything else you would expect of a language.
 
 Computing changes too fast to allow you to think you know it all. Keep up
 to date granddad.
 
 However what basic doesn't have is a portable language definition.

May you could give us an idea of the current state of basic affairs then by
translating the following example snippet:

It's me wrote:

 I saw this code from an earlier post:
 
 lst1 = [ab, ac, ba, bb, bc]
 lst2 = [ac, ab, bd, cb, bb]
 dct1 = dict.fromkeys(lst1)
 print [x for x in lst1 if x not in dct1]
 print [x for x in lst1 if x in dct1]
 
 It's simply remarkable for somebody to be able to do it so cleanly (and so
 obviously) - out of the box, if you may.
 
 Sure, you can do it in Basic.  Ur...sure?  Yes, sure...

Peter

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Re: setup.py - just what is it for ?

Richard Shea wrote:

 Hi - This is probably quite a stupid question but I've never
 understood what setup.py does. I've got a situation at the moment
 where I would like to use a script (which someone else has written and
 made available) to do CGI on a shared webserver to which I do not have
 shell access.

 The install instructions say run python setup.py but as far as I'm
 aware I cannot do that.

http://www.python.org/doc/current/inst/

 There is only one script involved (except for the setup.py !) and so
 I'm probably just going to copy it into my cgi-bin and give it a go
 but I'd like to know for future reference just how bad could it be if
 I did this ? Are there circumstances where you must use setup.py to
 have any hope of the code working ?

depends on the package, of course.  e.g. a package that includes C extensions
won't work if you don't compile the C extensions...

/F 



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Re: Help need with converting Hex string to IEEE format float

2004-12-17 Thread Ian Vincent

Max M [EMAIL PROTECTED] wrote in news:41bf121e$0$280
[EMAIL PROTECTED]:
 
 ##
 st = '80 00 00 00'
 
 import binascii
 import struct
 
 s = ''.join([binascii.a2b_hex(s) for s in st.split()])
 v = struct.unpack(f, s)[0]
 print v
 ##

This one worked great for what I was trying to do.

Thanks to everybody for your help.

TTFN

Ian
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Re: Why no list heritable type?

2004-12-17 Thread Sion Arrowsmith

In article [EMAIL PROTECTED], Mike Meyer  [EMAIL PROTECTED] wrote:
And before Python 2.2 there was the UserList class in the standard
library. Which is still there in 2.4. Shouldn't it be depreciated by
this point?

Apart from compatibility issues as mentioned in the UserList
documentation, deriving from it will give you a classic class,
whereas deriving from list will give you a new style class.
There may be circumstances under which this is important
(exercise left to more twisted minds than mine). Same applies
to dict/UserDict.

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  ___  |  Frankly I have no feelings towards penguins one way or the other
  \X/  |-- Arthur C. Clarke
   her nu becomeþ se bera eadward ofdun hlæddre heafdes bæce bump bump bump
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Re: Efficient grep using Python?

2004-12-17 Thread P

Christos TZOTZIOY Georgiou wrote:
On Thu, 16 Dec 2004 14:28:21 +, rumours say that [EMAIL PROTECTED]
I challenge you to a benchmark :-)

Well, the numbers I provided above are almost meaningless with such a
small set (and they easily could be reverse, I just kept the
convenient-to-me first run :).  Do you really believe that sorting three
files and then scanning their merged output counting duplicates is
faster than scanning two files (and doing lookups during the second
scan)?
$ python
Python 2.3.3 (#1, Aug 31 2004, 13:51:39)
[GCC 3.3.3 (SuSE Linux)] on linux2
Type help, copyright, credits or license for more information.
x=open('/usr/share/dict/words').readlines()
len(x)
45378
import random
random.shuffle(x)
open(/tmp/A, w).writelines(x)
random.shuffle(x)
open(/tmp/B, w).writelines(x[:1000])
$ time sort A B B | uniq -u /dev/null
real0m0.311s
user0m0.315s
sys 0m0.008s
$ time grep -Fvf B A /dev/null
real0m0.067s
user0m0.064s
sys 0m0.003s
(Yes, I cheated by adding the F (for no regular expressions) flag :)
Also you only have 1000 entries in B!
Try it again with all entries in B also ;-)
Remember the original poster had 100K entries!
and finally destroys original line
order (should it be important).
true
That's our final agreement :)
Note the order is trivial to restore with a
decorate-sort-undecorate idiom.
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Re: pywhich script - where is that module?

2004-12-17 Thread Dennis Benzinger

Thomas Guettler wrote:
 [...]
 Nice, you could add it to the python cookbook.
 [...]

Just in the case the OP doesn't know where to find the cookbook:
http://aspn.activestate.com/ASPN/Cookbook/Python/
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Re: BASIC vs Python

2004-12-17 Thread Peter Otten

Gerhard Haering wrote:

 In VB6, it would an exercise of working around the limitations of the
 data structures.
 
In MS Access I would probably end up with two database tables. The
juxtaposition of incredibly polished and virtually unusable features is
amazing.

Peter

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Re: do you master list comprehensions?

2004-12-17 Thread aleks90210

Thought you might enjoy my super-small flatten function: (though google
groups seems to be munging my whitespace today)

def flatten(d):
flatten([[[1,[2,3],[4,5]],6],[7]])==[1,2,3,4,5,6,7]
return reduce(lambda a,b:a+b,[(type(x) in (list, tuple) \
and flatten(x) or [x]) for x in d])

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Re: Efficient grep using Python?

2004-12-17 Thread sf

The point is that when you have 100,000s of records, this grep becomes
really slow?

Any comments?

Thats why I looked for python :)


 that would be

 grep -vf B A

 and it is a rare use of grep, indeed.
 -- 
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 Be strict when sending and tolerant when receiving. (from RFC1958)
 I really should keep that in mind when talking with people, actually...


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Re: setup.py - just what is it for ?

2004-12-17 Thread Fuzzyman

You could *try* writing a cgi which did something like
os.spawnv('python', ['setup.py', 'install']) (or whatever would be
right without looking up the docs)...

You sometimes don't need admin rights to run setup.py

I would be interested in the results.

Regards,

Fuzzy
http://www.voidspace.org.uk/atlantibots/pythonutils.html

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Re: setup.py - just what is it for ?

2004-12-17 Thread Fuzzyman

You could *try* writing a cgi which did something like
os.spawnv('python', ['setup.py', 'install']) (or whatever would be
right without looking up the docs)...

You sometimes don't need admin rights to run setup.py

I would be interested in the results.

Regards,

Fuzzy
http://www.voidspace.org.uk/atlantibots/pythonutils.html

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Re: Adding paths to sys.path permanently, and another problem...

Jeff Shannon wrote:
Judging from this, I think that os.environ['USERPROFILE'] seems like it 
may do what you want, though os.environ['APPDATA'] might be useful as 
well.  Of course, if you're trying to get something to work 
cross-platform, things may be more difficult -- but that's because 
Windows doesn't normally use ~ so its use is not supported very well.  
You may be able to create a $HOME that's equivalent to $USERPROFILE...

Both problems solved! The .pth seems like the best solution for the 
first one, and for the expanduser(~) I just added a $HOME variable to 
the Environment variables of WinXP. Simple solutions. Thanks Jeff

Amir
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Re: BASIC vs Python

2004-12-17 Thread Richards Noah (IFR LIT MET)


Christos TZOTZIOY Georgiou [EMAIL PROTECTED] wrote in message
news:[EMAIL PROTECTED]
 On Fri, 17 Dec 2004 01:43:56 -0600, rumours say that Mike Meyer
 [EMAIL PROTECTED] might have written:

 Assembler was better - at least you had recursion with
 assembler.

 You had recursion with BASIC --what you probably mean is that you had no
 stacked parameters (unless you imitated that with using an indexed
 array).

 90 rem recursion
 100 print beautiful colours
 110 gosub 100

I think he means that you had no recursive function calls in BASIC.  I
suppose, to most of us, recursion doesn't mean doing things more than
once, since by that definition, iteration is also recursion.  Recursion
generally means some type of self reference, like in functional languages,
where the simplest recursion is base case/recurring step.  BASIC didn't do
this, without a bit of unsightly hackery.  Then again, I don't believe that
it was really a concern at the time, so I don't suppose its too important of
an issue :)


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Re: Performance (pystone) of python 2.4 lower then python 2.3 ???

2004-12-17 Thread Andreas Kostyrka

Ok, here are my results, all python Versions supplied by Debian:

[EMAIL PROTECTED]:~ python1.5 /usr/lib/python1.5/test/pystone.py
Pystone(1.1) time for 1 passes = 1.33
This machine benchmarks at 7518.8 pystones/second
[EMAIL PROTECTED]:~ python2.2 /usr/lib/python1.5/test/pystone.py
Pystone(1.1) time for 1 passes = 1.03
This machine benchmarks at 9708.74 pystones/second
[EMAIL PROTECTED]:~ python2.3 /usr/lib/python1.5/test/pystone.py
Pystone(1.1) time for 1 passes = 0.73
This machine benchmarks at 13698.6 pystones/second
[EMAIL PROTECTED]:~ python2.4 /usr/lib/python1.5/test/pystone.py
Pystone(1.1) time for 1 passes = 0.66
This machine benchmarks at 15151.5 pystones/second

Run on a Knoppix/Debian based Duron 700 (Sony PCG-FX201 laptop).

I guess there must be differences in how your pythons got compiled, even
if you didn't specifies explicitly options.

Andreas

Am Mo, den 13.12.2004 schrieb Lucas Hofman um 17:09:
 Hi,
 
 Just installed Python 2.4 on a machine (RH8.0 Linux) that also has python 2.3
 and python 2.2 installed. The latter came with the linux distribution, the 
 other
 are compiled from source tarballs.
 
 Comparing them gives the following unexpected result:
 
 [EMAIL PROTECTED] test]$ /usr/bin/python pystone.py
 Pystone(1.1) time for 5 passes = 1.86
 This machine benchmarks at 26881.7 pystones/second
 [EMAIL PROTECTED] test]$ /usr/local/bin/python2.3 pystone.py
 Pystone(1.1) time for 5 passes = 1.22
 This machine benchmarks at 40983.6 pystones/second
 
 This is ok, a 52% speed increase, but:
 
 [EMAIL PROTECTED] test]$ /usr/local/bin/python2.4 pystone.py
 Pystone(1.1) time for 5 passes = 1.31
 This machine benchmarks at 38167.9 pystones/second
 
 A 7% speed DECREASE??? According to the documentation it should be a 5% 
 increase?
 
 The machine is a 3.0 GHz Xeon box.
 
 Both python 2.3 and 2.4 where configure without any options.
 
 Anyone who understands what is going on?
 
 Regards, Lucas


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Description: Dies ist ein digital signierter Nachrichtenteil
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decorator peculiarity

2004-12-17 Thread Diez B. Roggisch

Hi,

I just wrote my first decorator example - and  I already love them.

However I've encountered one peculiarity that strikes me odd:

When one writes a decorated function like this:

@decorate
def foo():
pass

the function decorate usually looks like this:

def decorate(func):
def _d(*args, **kwargs):
do_something()
# call func
func(*args, **kwargs)
return _d

So the function decorator has to return a function that is bound to the name
foo in the originating context (module or class) and gets the function
passed as argument.

But if I want my decorator to be parametrized, it looks like this:

@decorate(arg)
def foo():
pass

def decorate(arg):
def f(func):
def _d(*args, **kwargs):
do_something(arg)
# call func
func(*args, **kwargs)
return _d

So what happens is that an decorater with arguments is called with these,
returns a callable that then is called with foo, and the result is stored
under foo.

Now why this layer of indirection? I would have supposed that things look
like this:


def decorate(func, arg):
def _d(*args, **kwargs):
do_something(arg)
# call func
func(*args, **kwargs)
return _d

A sideeffect of this behaviour is that for a fully keyword-argumentized
function I still have to write parentheses:

@decorate()
def foo():
pass

def decorate(arg=None):
def f(func):
def _d(*args, **kwargs):
do_something(arg)
# call func
func(*args, **kwargs)
return _d

I don't mind the extra parentheses too much - it just made me wonder what
the rationale behind this is.

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Diez B. Roggisch
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Re: create lowercase strings in lists - was: (No subject)

2004-12-17 Thread Steve Holden

Mark Devine wrote:
I got the script working. Thanks for all your help everyone. Trouble is its not 
showing the correct results. Here is the script and results:
Well, that's a pretty unusual interpretation of the word working :-)
 [...]
I see from later postings you are getting closer to an answer, but 
obviously you still have to strip out the characters that you don't want 
to affect the match (such as ( and )).

regards
 Steve
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Re: Permission

2004-12-17 Thread Larry Bates

The function is os.rename(old, new).  If you actually
tried 'os.raname' (as your post suggests) that is an illegal
function.  I suspect that you mistyped it in your post,
but Peter's replys is correct.  Always copy and paste your
code and your traceback error message so it will be precise.
Permisssion denied means that you don't have permission to
rename this file.  Normally this is a rights issue.
BTW-os.rename works on XP.
Larry Bates
Syscon, Inc.
-g00t©- wrote:
--( oo )--
I don't know if there's a beginner board, just tell me if it's the place;
I tried Python this weekend. I'm java coder and I was looking for handling
names in os. I tried the os.raname('file.ext','nuFile.ext') and I got a
Permission denied error. In the docs, it say that it should work only for
UNIX, than it shouldn't work on XP (if I understood). I'm on XP, should I
declare something to enable permission, or is it common error?
Sorry about that newCommer question, but it would help, I'm on that problem
for a while...
--( oo )--
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Re: Potential improvement on delegation via explicit calls and super

2004-12-17 Thread Thomas Guettler

Am Fri, 17 Dec 2004 02:17:38 -0600 schrieb Robert Dick:

 Derived classes sometimes need to delegate portions of the work in overridden 
 methods to methods in their base classes.  This was traditionally done with 
 explicit calls in python, e.g.,
 
 class Base:
   def __init__(self):
 print 'base'
 
 class Left(Base):
   def __init__(self, arg):
 Base.__init__(self)
 print 'left'
 
 class Right(Base):
   def __init__(self, arg):
 Base.__init__(self)
 print 'right'

If you can change the source of Base, I would do it like
this:

class Base:
_init_done=0
def __init__(self):
if self._init_done:
return
self._init_done=1

# ... do init


 Thomas

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Request for Help in OpenSourcing a Project

2004-12-17 Thread Colin Meeks

I love Python and started back when 1.52 was the popular version.
Whilst learning Python, I created a website framework called [EMAIL PROTECTED],
which I run at the following two sites :

http://www.meeks.ca
All content is done in [EMAIL PROTECTED] and static pages are created.

http://www.programmedintegration.com
All content is created dynamically.

[EMAIL PROTECTED] is a mix between a CMS and web framework.  I've been
personally using it for more than 5 years, however it's never formally
been completed and has a lot of rough edges. I created [EMAIL PROTECTED] to
handle all data as straight text files, as my provider at the time,
had no facilities for databases, so this is a definite area that
[EMAIL PROTECTED] could be expanded.

What I'm basically after is someone to assist in polishing up the
product and ultimately releasing as OpenSource or some similar kind of
license, whereby I retain copyright, but the use of the product is
free. Also if anyone has any tips or advice, I'd be most grateful. 
I'm loathe to release the code at present, as it's really quite
embarassing in places, and has a strong need for markup code to be
removed from within program code and placed as separate files.

Anyway if anyone is able to assist or advise, I'd be more than happy
to discuss things futher.

Regards

Colin
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Re: BASIC vs Python

Richards Noah wrote:

 You had recursion with BASIC --what you probably mean is that you had no
 stacked parameters (unless you imitated that with using an indexed
 array).

 90 rem recursion
 100 print beautiful colours
 110 gosub 100

 I think he means that you had no recursive function calls in BASIC.  I
 suppose, to most of us, recursion doesn't mean doing things more than
 once, since by that definition, iteration is also recursion.  Recursion
 generally means some type of self reference

Note that he uses gosub, not goto.  The code block that starts at line 100
and ends at line 110 calls itself recursively.  Works just fine in many (most?)
BASIC implementations (at least until you run out of call stack).

(the original BASIC was a different thing, though: quoting from the 1964 hand-
book: the user must be very careful not to write a program in which GOSUB
appars inside a subroutine which itself is entered via a GOSUB; it just won't
work.  The handbook also states that the program size is limited to two feet
of teletype paper...)

/F 



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Dr. Dobb's Python-URL! - weekly Python news and links (Dec 15)

2004-12-17 Thread Cameron Laird

QOTW: [Python demands more thought in optimization, because i]n
other languages, by the time you get the bloody thing working it's
time to ship, and you don't have to bother worrying about making
it optimal. -- Simon Brunning

One of the best features of c.l.py is how questions phrased in the
most ambiguous terms are often slowly elaborated into meaningful
enquiries. -- Steve Holden

Martin Bless summarizes in an extremely valuable post what
you need to know to generate Python-related executable binaries
targeted for Windows*.

http://groups-beta.google.com/group/comp.lang.python/browse_thread/thread/73f29284d1e031c7/

John Hunter, Fredrik Lundh, Pádraig Brad, and Tim Peters
work out in public on a model problem of textual analysis.

http://groups-beta.google.com/group/comp.lang.python/browse_thread/thread/b009627e9a5abc64/7d75f531ba8a7fe2

Amidst the usual combination of heat and light (in this case,
on commercial acceptance and applicability of OO), Mike Meyer
narrates from his own experience an example of how good object
orientation can be.

http://groups-beta.google.com/group/comp.lang.python/browse_thread/thread/16590f4138b6a978/

gDesklets are attention-grabbing Py-scriptable desktop decorations.
http://gdesklets.gnomedesktop.org/index.php

Sure, a list comprehension can comprise multiple for-s.

http://groups-beta.google.com/group/comp.lang.python/browse_thread/thread/ee5f7f8c227b22ff/

Mac OS X makes for highly-desired (at least by some) development
hosts; moreover there are three killer features in MacPython
that you can't get anywhere else ...
http://mail.python.org/pipermail/pythonmac-sig/2004-December/012298.html

Everything Python-related you want is probably one or two clicks away in
these pages:

Python.org's Python Language Website is the traditional
center of Pythonia
http://www.python.org
Notice especially the master FAQ
http://www.python.org/doc/FAQ.html

PythonWare complements the digest you're reading with the
marvelous daily python url
http://www.pythonware.com/daily
Mygale is a news-gathering webcrawler that specializes in (new)
World-Wide Web articles related to Python.
http://www.awaretek.com/nowak/mygale.html
While cosmetically similar, Mygale and the Daily Python-URL
are utterly different in their technologies and generally in
their results.

comp.lang.python.announce announces new Python software. Be
sure to scan this newsgroup weekly.

http://groups.google.com/groups?oi=djqas_ugroup=comp.lang.python.announce

Brett Cannon continues the marvelous tradition established by
Andrew Kuchling and Michael Hudson of intelligently summarizing
action on the python-dev mailing list once every other week.
http://www.python.org/dev/summary/

The Python Package Index catalogues packages.
http://www.python.org/pypi/

The somewhat older Vaults of Parnassus ambitiously collects references
to all sorts of Python resources.
http://www.vex.net/~x/parnassus/

Much of Python's real work takes place on Special-Interest Group
mailing lists
http://www.python.org/sigs/

The Python Business Forum further[s] the interests of companies
that base their business on ... Python.
http://www.python-in-business.org

Python Success Stories--from air-traffic control to on-line
match-making--can inspire you or decision-makers to whom you're
subject with a vision of what the language makes practical.
http://www.pythonology.com/success

The Python Software Foundation (PSF) has replaced the Python
Consortium as an independent nexus of activity. It has official
responsibility for Python's development and maintenance.
http://www.python.org/psf/
Among the ways you can support PSF is with a donation.
http://www.python.org/psf/donate.html

Kurt B. Kaiser publishes a weekly report on faults and patches.
http://www.google.com/groups?as_usubject=weekly%20python%20patch

Cetus collects Python hyperlinks.
http://www.cetus-links.org/oo_python.html

Python FAQTS
http://python.faqts.com/

The Cookbook is a collaborative effort to capture useful and
interesting recipes.
http://aspn.activestate.com/ASPN/Cookbook/Python

Among several Python-oriented RSS/RDF feeds available are
http://www.python.org/channews.rdf
http://bootleg-rss.g-blog.net/pythonware_com_daily.pcgi
http://python.de/backend.php
For more, see
http://www.syndic8.com/feedlist.php?ShowMatch=pythonShowStatus=all
The old Python To-Do List now lives principally in a
SourceForge reincarnation.

Re: Cool object trick

2004-12-17 Thread Steve Holden

Fredrik Lundh wrote:
Steve Holden wrote:

Certainly makes writing 'print obj.spam, obj.spam, obj.eggs, obj.bacon,
obj.sausages, and, obj.spam' a lot easier ;-)
Of course this whole thing of substituting attribute access for dictionary keys only works as long 
as the keys are strings with the same syntax as Python identifiers, so one shouldn't go completely 
overboard.

unless you're willing to use getattr() for thos oddball cases, of course.
Of course.
 class Dummy:
... pass
...
 x = Dummy()
 setattr(x, spamegg, hello)
 getattr(x, spamegg)
'hello'
 x.spamegg
Traceback (most recent call last):
  File stdin, line 1, in ?
AttributeError: Dummy instance has no attribute 'spam'
but seriously, turning container elements into attributes should only be done
if it makes sense from a design perspective.  (and vice versa; you shouldn't
use a dictionary if an object would make more sense -- but attribute abuse
is a lot more common)
Really we are talking about the outer limits here. Anyone preferring
setattr(x, spamegg, hello)
to
x[spamegg] = hello
when it isn't necessary clearly doesn't share our two principal 
attributes: an elegant sense of design, fine knowledge of Python and an 
   inherent modesty.

Sorry: out *three* principal attributes. Bugger, I'll come in again.
regards
 Steve
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Python Web Programming  http://pydish.holdenweb.com/
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Re: BASIC vs Python

2004-12-17 Thread Steve Holden

Steve Holden wrote:
Adam DePrince wrote:
On Thu, 2004-12-16 at 13:36, abisofile wrote:
hi
I'm new to programming.I've try a little BASIC so I want ask since 
Python is also interpreted lang if it's similar to BASIC.

Nobody is answering this question because they are shuddering in fear
and revulsion.
During the 1980's BASIC was the language to embedd into the ROM's of the
computers of the day.   This was in a misguided effort to make computers
understandable to their target audience.  The goal of the day was to
build a system that a manager would want to buy; it was believed that
the only way for a manager to see the value of a system was to make the
language understandable to said manager.  The expectation, of course,
that the manager would sit down and play with the computer instead of
delegating the tasks to somebody more qualified is somewhat misguided in
hindsight.  To do that, a language that closely resembled the process of
micromanaging an untrained worker was employed.
But that language was COBOL, not BASIC. BASIC is actually an acronym for 
Beginners' All-purpose Symbolic Instruction Code, which the initial 
implementations at Dartmouth weren't, really. The big innovation was the 
use of line-numbering to allow interactive editing and testing of a 
program.

Which, now I remember, Digital Equipment extended to floating-point in 
their FOCAL language. I never did discover whether the number of 
insertions required was limited by the floating-point precision, but 
Focal was unique in my experience in allowing insertion of statement 1.5 
between statements 1 and 2.

(mumbles into beard and drools quietly in the corner).
talking-to-myself-again-ly y'rs  - steve
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Python Web Programming  http://pydish.holdenweb.com/
Holden Web LLC  +1 703 861 4237  +1 800 494 3119
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Re: Email filters in python

2004-12-17 Thread Simon Brunning

On Fri, 17 Dec 2004 15:07:26 GMT, sf [EMAIL PROTECTED] wrote:
 Would someome like to post their email filters code. Its so common that
 probably some standard library
 supports it or many would have written it already. If I have basic
 structure, I can take from there.

http://spambayes.sourceforge.net/

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Cheers,
Simon B,
[EMAIL PROTECTED],
http://www.brunningonline.net/simon/blog/
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Re: Time Difference

GMane Python [EMAIL PROTECTED] wrote:

  I was wondering if there is an existing function that would let me
 determine the difference in time.  To explain:

 Upon starting a program:

 startup = time.time()

 After some very long processing:
 now = time.time()

 print days hours minutes seconds, now - startup

 So, to print in a formatted way (D-H-M-S) the difference in time of startup
 and now.

now - startup gives you the difference in seconds; turning that into (days,
hours, minutes, seconds) isn't that hard (hint: lookup the divmod function
in the manual).

or you could use the datetime module:

 from datetime import datetime
 startup = datetime.today()
 now = datetime.today()
 print now - startup
0:00:06.625000

(see the library reference for details).

/F 



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Re: Email filters in python

2004-12-17 Thread Diez B. Roggisch

 ..
 - open POP-SSL connection to pop.someserver.com
 - Get all mails and store as Unix mail file (mymails)
 - do not delete mails from server
 - close connection.
 ..
 - open mymails file
 
 - Do following for each mail in mymails file (one by one)
 {
 - get header fields:  {FROM, TO, CC, Subject,... more ... }
 - some conditons (FROM is found my addresslist.txt but not part of
 my rejectlist.txt )
 append that mail to some existing file.
 }

For these two, use fetchmail and procmail.
 ..
 - open SMTP-TLS connection to smtp.someserver.com
 - send all mails in my unix mail file
 - close connection

I'm not totally sure how to do this best - but here python might indeed
help, using smtplib and mailbox.

-- 
Regards,

Diez B. Roggisch
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Re: Efficient grep using Python?

2004-12-17 Thread TZOTZIOY

On Fri, 17 Dec 2004 14:22:34 +, rumours say that [EMAIL PROTECTED]
might have written:

sf:

sf wrote:
 The point is that when you have 100,000s of records, this grep becomes
 really slow?

There are performance bugs with current versions of grep
and multibyte characters that are only getting addressed now.
To work around these do `export LANG=C` first.

You also should use the -F flag that Pádraig suggests, since you don't
have regular expressions in the B file.

In my experience grep is not scalable since it's O(n^2).
See below (note A and B are randomized versions of
/usr/share/dict/words (and therefore worst case for the
sort method)).

$ wc -l A B
   45427 A
   45427 B

$ export LANG=C

$ time grep -Fvf B A
real0m0.437s

$ time sort A B B | uniq -u
real0m0.262s

$ rpm -q grep coreutils
grep-2.5.1-16.1
coreutils-4.5.3-19

sf, you better do your own benchmarks (there is quick, sample code in
other posts of mine and Pádraig's) on your machine, since on my test
machine the numbers are reversed re to these of Pádraig's (grep takes
half the time).

package versions (on SuSE 9.1 64-bit):

$ rpm -q grep coreutils
grep-2.5.1-427
coreutils-5.2.1-21

language:
$ echo $LANG
en_US.UTF-8

Caution: both solutions are interexchangeable as long as you don't have
duplicate lines in the A file.  If you do, use the grep version.
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Be strict when sending and tolerant when receiving. (from RFC1958)
I really should keep that in mind when talking with people, actually...
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Re: [OT] Python IDE

2004-12-17 Thread Dan Perl


Fuzzyman [EMAIL PROTECTED] wrote in message 
news:[EMAIL PROTECTED]

 Dan Perl wrote:
 Mike Meyer [EMAIL PROTECTED] wrote in message
 news:[EMAIL PROTECTED]
  Dan Perl [EMAIL PROTECTED] writes:
 
  Mike Meyer [EMAIL PROTECTED] wrote in message
  news:[EMAIL PROTECTED]
  A: What's the most obnoxious thing on Usenet?
  Q: topposting.
 
  What is Jeopardy, Alex?  You got your QA mixed up.
 
  No, the QA in that order demonstrate what's wrong with top
 posting.
 
 mike
  --
  Mike Meyer [EMAIL PROTECTED] http://www.mired.org/home/mwm/
  Independent WWW/Perforce/FreeBSD/Unix consultant, email for more
  information.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

 Yeah, you're right.
 .






























 If it's a short reply to a long post - in context - top posting is
 often *significantly * less annoying..

 Isn't there a quote that includes 'hobgobline of little minds'..

 Regards,
 Fuzzy
 http://www.voidspace.org.uk/atlantibots/pythonutils.html


That was my point.  I was being sarcastic again but I didn't put a warning 
anymore.  As I'm doing now, still posting at the bottom of a long posting.

I'm not sure whether you were attacking me too (am I the little mind?) or 
supporting me, Fuzzy.  Anyway, I think that Mike Meyer was more annoyed by 
my jab at US politics than by my top posting.  But it was safer for him to 
pick on the latter.

Dan 


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Fwd: Re: create lowercase strings in lists - was: (No subject)

I got this working now. Thanks everybody for your help.

_
Sign up for eircom broadband now and get a free two month trial.*
Phone 1850 73 00 73 or visit http://home.eircom.net/broadbandoffer

---BeginMessage---
Happy to help. Pass it on.
regards
 Steve
Mark Devine wrote:
I got it working correctly now thanks. I was on the right track it was a subset not a superset that was required in the end and all has worked out fine for me. Thank you for all your help 

Steve Holden [EMAIL PROTECTED] wrote:

Mark Devine wrote:

I got the script working. Thanks for all your help everyone. Trouble is its not 
showing the correct results. Here is the script and results:
Well, that's a pretty unusual interpretation of the word working :-)
 [...]
I see from later postings you are getting closer to an answer, but 
obviously you still have to strip out the characters that you don't want 
to affect the match (such as ( and )).

regards
 Steve
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Python Web Programming  http://pydish.holdenweb.com/
Holden Web LLC  +1 703 861 4237  +1 800 494 3119



_
Sign up for eircom broadband now and get a free two month trial.*
Phone 1850 73 00 73 or visit http://home.eircom.net/broadbandoffer



--
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Python Web Programming  http://pydish.holdenweb.com/
Holden Web LLC  +1 703 861 4237  +1 800 494 3119
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RE: Cool object trick

2004-12-17 Thread Robert Brewer

Alex Stapleton wrote:
 you can't do

 var = varA
 obj = struct(varA = Hello)
 print obj.var

 and expect it to say Hello to you.

Did you mean print obj.varA? I can't think of any use case for the way
you wrote it, so I'm naively guessing you've got a typo. Feel free to
correct me. ;)

 class struct(object):
... def __init__(self, **kwargs):
... self.__dict__.update(kwargs)
... 
 var = varA
 obj = struct(**{str(var): Hello})
 print obj.varA
Hello


Robert Brewer
MIS
Amor Ministries
[EMAIL PROTECTED]
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Re: ftp

2004-12-17 Thread hawkmoon269

That's a good idea.  Thanks! :-)

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Troubleshooting: re.finditer() creates object even when no match found

2004-12-17 Thread Chris Lasher

Hello,
I really like the finditer() method of the re module. I'm having
difficulty at the moment, however, because finditer() still creates a
callable-iterator oject, even when no match is found. This is
undesirable in cases where I would like to circumvent execution of code
meant to parse out data from my finditer() object.

I know that if I place a finditer() object in an iterative for loop,
the loop will not execute, but is there some way I can test to see if
the object contains no matches in the first place? I thought about
using .next() but I don't want to lose the ability to process the first
(sometimes only) match in the finditer() object.
Thanks in advance,
Chris

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Re: wxPython question

2004-12-17 Thread M.E.Farmer


André wrote:
 I needed to scale the image down to 16 by 16 on my Windows computer
to
 make it work.

Hello André,

# I actually ran this code ;)
import wx
app = wx.PySimpleApp()
class myframe(wx.Frame):
def __init__(self):
wx.Frame.__init__(self,None,-1,Icon Frame,
size=(100,100),pos=(-1,-1))
frame = myframe()
wx.InitAllImageHandlers()
# this image is 32*32 on my computer
image = wx.Image('c:/Python22/pycon.ico', wx.BITMAP_TYPE_ANY)
image = image.ConvertToBitmap()

icon = wx.EmptyIcon()
icon.CopyFromBitmap(image)

frame.SetIcon(icon)

frame.Show()
app.MainLoop()

This works fine for me I am on windows 2000, and pycon.py is 32*32*24
Wonder why you had to resize?

On another note, be sure to check out the tools dir in either the
wxpython dir or wx dir it has a script called img2py.py.

img2py.py  --  Convert an image to PNG format and embed it in a Python
module with appropriate code so it can be loaded into
a program at runtime.  The benefit is that since it is
Python source code it can be delivered as a .pyc or
'compiled' into the program using freeze, py2exe, etc.

Be sure to use the -i flag so it will convert it to a wxIcon
Once you convert your icon to source using img2py.py you can do this:
import Icon
ICON = Icon.getIcon()
 frame.SetIcon(ICON)

Hth, 
 M.E.Farmer

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A completely silly question

This must be the silliest question ever:
What about user input in Python? (like stdin)
Where can I find it? I can't find any references to it in the documentation.
Amir
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Re: A completely silly question

2004-12-17 Thread Frans Englich

On Friday 17 December 2004 16:40, Amir Dekel wrote:
 This must be the silliest question ever:

 What about user input in Python? (like stdin)
 Where can I find it? I can't find any references to it in the
 documentation.

See sys.stdin


Cheers,

Frans
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RE: A completely silly question

2004-12-17 Thread Batista, Facundo

Title: RE: A completely silly question





[Amir Dekel]


#- What about user input in Python? (like stdin)
#- Where can I find it? I can't find any references to it in 
#- the documentation.


sys.stdin


http://docs.python.org/lib/module-sys.html


. Facundo


  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Re: A completely silly question

2004-12-17 Thread Harlin Seritt

Amir Dekel wrote:

 This must be the silliest question ever:
 
 What about user input in Python? (like stdin)
 Where can I find it? I can't find any references to it in the
 documentation.
 
 Amir

Simple, Simple, Simple:

Var = raw_input(Some prompting text here: )


-- 
Harlin Seritt
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Re: Cool object trick

Robert Brewer wrote:
Alex Stapleton wrote:
you can't do
var = varA
obj = struct(varA = Hello)
print obj.var
and expect it to say Hello to you.
Did you mean print obj.varA?
I believe he meant that he wanted the equivalent of:
getattr(obj, var)
Steve
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Re: BASIC vs Python

2004-12-17 Thread It's me


Gregor Horvath [EMAIL PROTECTED] wrote in message
news:[EMAIL PROTECTED]
 It's me wrote:
  Absolutely *ugly*!
 
  But still, your point is well taken.  Thank you for pointing this out.
 
  Adam was right:
 
  Don't do it, unless your goal is simply to embarrass and insult
  programmers.


 OK. Then please schow me, how you can create a complex form with grids,
 explorer like trees etc. in 2 minutes in standard python.

 Or make any given standard python object accessible from MS Excel in 2
 minutes.

 --
 Greg

I thought we are talking about the language, are we not?

--
It's me


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Re: lies about OOP

2004-12-17 Thread Aahz

In article [EMAIL PROTECTED],
Peter Hansen  [EMAIL PROTECTED] wrote:

P.S.: I'm only half Danish, but the other half is from a particularly
bloodthirsty line of Canadians.

Oh, you're part Quebecois?
-- 
Aahz ([EMAIL PROTECTED])   * http://www.pythoncraft.com/

19. A language that doesn't affect the way you think about programming,
is not worth knowing.  --Alan Perlis
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deprecate UserList? (WAS: Why no list heritable type?)

Sion Arrowsmith wrote:
In article [EMAIL PROTECTED], Mike Meyer  [EMAIL PROTECTED] wrote:
And before Python 2.2 there was the UserList class in the standard
library. Which is still there in 2.4. Shouldn't it be depreciated by
this point?

Apart from compatibility issues as mentioned in the UserList
documentation, deriving from it will give you a classic class,
whereas deriving from list will give you a new style class.
There may be circumstances under which this is important
(exercise left to more twisted minds than mine). Same applies
to dict/UserDict.
Classic classes will eventually disappear:
http://www.python.org/doc/2.2.3/whatsnew/sect-rellinks.html#SECTION00031
GvR also encourages people to use new-style classes for everything:
http://mail.python.org/pipermail/python-dev/2002-March/021817.html
Steve
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Re: Python RSS aggregator?

2004-12-17 Thread Evan Simpson

Erik Max Francis wrote:
I've checked and all the feeds _I_ care about :-) are available in RSS 
now, so it would make sense to move to an RSS aggregator if it has the 
same features.  I've looked around at some that are available, both in 
Python and not, and haven't found anything that had the feature set I 
want.  One in Python would obviously be a huge benefit.
http://www.nongnu.org/straw/ would be a great place to start, even if it 
doesn't have all of your desired features.

Cheers,
Evan @ 4-am
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Re: BASIC vs Python

Christos TZOTZIOY Georgiou [EMAIL PROTECTED] writes:

 On Fri, 17 Dec 2004 01:43:56 -0600, rumours say that Mike Meyer
 [EMAIL PROTECTED] might have written:
Assembler was better - at least you had recursion with
assembler.
 You had recursion with BASIC --what you probably mean is that you had no
 stacked parameters (unless you imitated that with using an indexed
 array).

Quite right. My bad.

  mike
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Re: Python mascot proposal

2004-12-17 Thread Nick Vargish

EP [EMAIL PROTECTED] writes:

 (what is the mascot for C++?)

I can't seem to find a goatse link... (But I didn't try very hard.)

Nick

-- 
#  sigmask  ||  0.2  ||  20030107  ||  public domain  ||  feed this to a python
print reduce(lambda x,y:x+chr(ord(y)-1),' Ojdl!Wbshjti!=obwAcboefstobudi/psh?')
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Re: Request for Help in OpenSourcing a Project

2004-12-17 Thread fuzzylollipop

www.sourceforge.net

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Re: A completely silly question

Harlin Seritt wrote:
Simple, Simple, Simple:
Var = raw_input(Some prompting text here: )
Frans Englich wrote:

 See sys.stdin

What I need from the program is to wait for a single character input, 
something like while(getchar()) in C. All those Python modules don't 
make much sence to me...

Amir
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Re: A completely silly question

Amir Dekel wrote:
What I need from the program is to wait for a single character input, 
something like while(getchar()) in C. All those Python modules don't 
make much sence to me...
sys.stdin.read(1)
but if you're having trouble reading the module documentation, maybe you 
could elaborate on what's giving you trouble.  The answer to 99% of 
questions on this list is in the documentation somewhere, so if you 
don't know how to read it, you're going to have trouble with Python.

Steve
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Re: Time Difference

2004-12-17 Thread Peter Hansen

GMane Python wrote:
Hello
  I was wondering if there is an existing function that would let me
determine the difference in time.  To explain:
Upon starting a program:
startup = time.time()
After some very long processing:
now = time.time()
print days hours minutes seconds, now - startup
So, to print in a formatted way (D-H-M-S) the difference in time of startup
and now.
 from datetime import datetime
 startTime = datetime.now()
   # processing
 endTime = datetime.now()
 print 'elapsed', endTime - startTime
elapsed 0:00:09.063000
-Peter
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Re: BASIC vs Python

2004-12-17 Thread Adam DePrince

On Fri, 2004-12-17 at 10:14, Steve Holden wrote:
  Nobody is answering this question because they are shuddering in fear
  and revulsion.
  During the 1980's BASIC was the language to embedd into the ROM's of the
  computers of the day.   This was in a misguided effort to make computers
  understandable to their target audience.  The goal of the day was to
  build a system that a manager would want to buy; it was believed that
  the only way for a manager to see the value of a system was to make the
  language understandable to said manager.  The expectation, of course,
  that the manager would sit down and play with the computer instead of
  delegating the tasks to somebody more qualified is somewhat misguided in
  hindsight.  To do that, a language that closely resembled the process of
  micromanaging an untrained worker was employed.
 
  But that language was COBOL, not BASIC. BASIC is actually an acronym for 

It was a common theme and more than one language embraced it.  The PET
20 wasn't exactly going to run COBOL any time soon.

To be fair, COBOL resembled the micromanaging of a well trained worker,
an accountant or actuary perhaps.

Notice that today every white collar employee that can afford to keep
the heat running in their office during the winter fantasizes their
operation as being enterprise class?  The same was true 20 years ago -
but it was the mere presence of the computer that served a similar
role.  If you were really enterprise class, you used COBOL.  And if you
were in the wannabe category, you got yourself a PET 20 and told it what
to do in BASIC.

 (mumbles into beard and drools quietly in the corner).

Adam DePrince 


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Re: A completely silly question

2004-12-17 Thread Peter Hansen

Amir Dekel wrote:
What I need from the program is to wait for a single character input, 
something like while(getchar()) in C. 
Try the msvcrt module if you are on Windows.
If you are not, remember to specify your platform next time
you ask a question...
All those Python modules don't 
make much sence to me...
That's going to make it hard to program in Python, I suspect.
Maybe it would be helpful to run through the tutorial, or
spend more time reading the docs.
-Peter
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Re: Create linear spaced vector?

2004-12-17 Thread Adam DePrince

On Fri, 2004-12-17 at 13:39, kjm wrote:
 Hi Everyone,
 
 I am trying to port some old MatLab code to python, and am stuck on
 how to accomplish something.
 
 I am trying to write a generalized function that will create a
 linearly spaced vector, given the start and end point, and the number
 of entries wanted.
 
 In MatLab I have this function that I wrote:
 
 [code]
 
 function out = linearspace(x1,x2,n)
 
 out = [x1+ (0:n-2)*(x2 - x1)/(floor(n)-1) x2];
 
 return
 
 
 [/code]
 
 
 I have the numeric package, numarray installed, and I think it should
 be accomplished easily, but I just can't seem to get the syntax
 correct with python.
 
 Any tips would be greatly appreciated.
 
 
 Thanks

Is this want you want?

#!/usr/bin/python

def linear_space( start, end, count ):

 Returns a vector containing count evently spaced intervals
(count + 1 evenly spaced points) 

delta = (end-start) / float(count)
return [start,] + \
map( lambda x:delta*x + start, range( 1, count  ) ) + [end, ] 

if __name__ == __main__:
print linear_space( 1.0, 2.0, 10 )

Running it gives you: 
 [1.0, 1.1001, 1.2, 1.3, 1.3999, 1.5,
1.6001, 1.7002, 1.8, 1.8999, 2.0]



Adam DePrince 


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Re: Why are tuples immutable?

2004-12-17 Thread Jeff Shannon

Antoon Pardon wrote:
Op 2004-12-17, Jeff Shannon schreef [EMAIL PROTECTED]:
 

To take another approach -- given some function that allows lists to 
(pretend to be) hashable:

. key = [1,2]
. d[key] = 'foo'
. d[[1,2]]

. key.append(3)
. d[key]
???
.
As I understand it, it is impossible for there to be a hash function for 
which both of these cases can return the same object.
   

How about:
 hash = id
 

If hash equals id, then the first of those cases fails.  I'm creating a 
new list with the same value but different.  If hash *doesn't* equal id, 
then the second case fails.  It's an either-or proposition; you *cannot* 
have both with mutable objects.  And the proper definition of a hash 
requires that you have both.

Now, even if hash were made to equal id... suppose I then pass that dict 
to a function, and I want to get the value that I've stored under 
[1,2].  In order to do that, I'd *also* have to pass in the *exact* list 
that I used as the key, because *only* that *exact* instance will hash 
correctly.  Not only that, but if I've got a handful of such values that 
I want to retrieve, I'll have to pass in *all* of the lists that I used 
to key the dict.  Any time I want to use the dict elsewhere, I need to 
pass not only the dict itself, but a list of keys to the dict.  And then 
I need to know the order of the keys in that list.  Ugh.

I suppose I could just use keys() to get a complete list of keys from 
the dict itself.  But still, I'd have to iterate over keys() to try to 
find the proper list that matches the value that I need, and then use 
the key to reference the dict.  That leaves me with code like this:

   def process_dict(d):
   for key in d.keys():
   if key == [1,2]:
   value1 = d[key]
   if key == [1,3]:
   value2 = d[key]
   if key == [2,2]:
   # and so on
Double ugh.
You also make the fault that because people ask for the possibility of
keys being mutable objects, that they want to mutate those object while 
being a key.
 

If mutable objects can be used as dict keys, then dicts *must* be able 
to sensibly handle the keys being mutated underneath of them, because it 
*will* happen. 

Your assumption that it's okay to make keys mutable, just tell 
programmers not to do it, is along the same lines as assuming that 
memory leaks in C aren't a problem because you've told programmers to 
free() all of the memory that they malloc()'d. 

In order to maintain the logical consistency that if an object is used 
as a dict key, that same object should reasonably be expected to 
retrieve the same value, identity-based hashes are necessary.  As a 
result, the first option must be disallowed.
   

Then why don't we disallow lists of mutable objects to be sorted or
to be made into a heap. In fact each time we have a structure that
relies on some invariant among its members we should disallow mutable
members because with mutable members the invariant can be violated
without ever rebinding one of the elements.
 

If we have an object that, *by definition*, has some invariant that can 
be violated by having mutable members, then sure.  But lists aren't 
sorted or heaped by definition.

Note also that, if a list becomes unsorted or unheaped, it's fairly easy 
to resort or re-heapify the list.  It may take some time, but nothing is 
lost.  If a dictionary key mutates, then data *is* lost. 

In either case, if it's ever possible for equality to change while 
identity doesn't, then somewhere along the lines one of the core 
requirements, the contract if you will, of a dictionary *must* be 
broken.  And while it may be possible to get away with breaking that 
contract some of the time (by postulating, for example, that if one 
mutates a dict key then things will break), this will result in more 
bugs and more confusion over time.  There is no way for Python to be 
able to behave consistently in the face of mutable dict keys, therefore 
(In the face of ambiguity, refuse the temptation to guess.) Python 
declines the temptation of making it trivial to use mutable objects as 
dict keys.
   

As it turns out, python makes no difference in difficulty for making
either mutable or immutable objects usable as dictionary keys. The
only difference is that python only made its standard immutable
types hashable and not its standard mutable objects.
 

No -- the mathematical definition of 'hashable' fails for mutable types, 
and Python doesn't try to pretend that it can hash mutable types.  
Python also provides features so that user-defined immutable types can 
be hashed properly, and those features can be abused to pretend to hash 
user-defined mutable types,  but that's not the same as saying that 
Python is happy with mutable dictionary keys.  (One can abuse __add__() 
to do all sorts of things other addition, too, but it would still be a 
stretch to say that Python supports using + to do multiplication, it 
just doesn't provide it on

Re: [OT] Python IDE

Q: What's the second most annoying thing to do on Usenet?
A: Fail to properly trim quotes.

Dan Perl [EMAIL PROTECTED] writes:

 Fuzzyman [EMAIL PROTECTED] wrote in message 
 news:[EMAIL PROTECTED]
 Dan Perl wrote:
 Mike Meyer [EMAIL PROTECTED] wrote in message
 news:[EMAIL PROTECTED]
  Dan Perl [EMAIL PROTECTED] writes:
  Mike Meyer [EMAIL PROTECTED] wrote in message
  news:[EMAIL PROTECTED]
  A: What's the most obnoxious thing on Usenet?
  Q: topposting.
  What is Jeopardy, Alex?  You got your QA mixed up.
  No, the QA in that order demonstrate what's wrong with top
 posting.
 Yeah, you're right.
 If it's a short reply to a long post - in context - top posting is
 often *significantly * less annoying..

When replying to a long post, you should trim the post to the relevant
parts. This goes a long way towards solving that problem. Even if the
relevant parts are rather long, it's still better to not top post,
because that'll leave things out of order for replies.

 I'm not sure whether you were attacking me too (am I the little mind?) or 
 supporting me, Fuzzy.  Anyway, I think that Mike Meyer was more annoyed by 
 my jab at US politics than by my top posting.  But it was safer for him to 
 pick on the latter.

You're wrong. I don't even remember seeing any comment about american
politics in your post.

 mike
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Re: Why no list heritable type?

Jeff Shannon [EMAIL PROTECTED] writes:

 Sion Arrowsmith wrote:
 Additionally, as I understand it UserList and UserDict are implemented
 entirely in Python, which means that there can be significant
 performance differences as well.

Actually, UserList and UserDict are just wrappers around the builtin
types. So the performance hit is one Python function call - pretty
much neglible. But new code should still subclass the builtins.

 mike
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Re: Create linear spaced vector?

2004-12-17 Thread kjmacken

Thanks for the code snippets guys.  Exactly what I needed to get going.

I knew I could get the solution from matplotlib, but getting it
installed using Fink (OS X) has been giving me a headache, so I thought
I could just write my own function for now to get a small piece of code
written

The help is greatly appreciated.

kjm

John Hunter wrote:
  kjm == kjm  [EMAIL PROTECTED] writes:

 kjm Hi Everyone, I am trying to port some old MatLab code to
 kjm python, and am stuck on how to accomplish something.

 kjm I am trying to write a generalized function that will create
 kjm a linearly spaced vector, given the start and end point, and
 kjm the number of entries wanted.

 kjm In MatLab I have this function that I wrote:

 kjm [code]

 kjm function out = linearspace(x1,x2,n)

 in matlab the builtin function to accomplish this is linspace

 The python package matplotlib defines a host of matlab compatible
 functions, including linspace

 def linspace(xmin, xmax, N):
if N==1: return xmax
dx = (xmax-xmin)/(N-1)
return xmin + dx*arange(N)


 Note that matplotlib extends the Numeric/numarray core of matlab
 compatible functions (defined in MLab) to include plotting functions

   http://matplotlib.sourceforge.net

 A listing of matlab compatible functions is provided at
 http://matplotlib.sourceforge.net/matplotlib.pylab.html
 
 
 JDH

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Re: BASIC vs Python

2004-12-17 Thread Dan Bishop

Peter Otten wrote:
 Peter Hickman wrote:

  Mike Meyer wrote:
  BASIC as implented by Microsoft for the Apple II and the TRS 80
(among
  others) is simply the worst programming language I have ever
  encountered. Assembler was better - at least you had recursion
with
  assembler.
 
  Basic has progressed much since you last looked at it, time to
update your
  facts. Basic has recursion, it compiles to native code, it has
objects,
  can be event driven and everything else you would expect of a
language.
 
  Computing changes too fast to allow you to think you know it all.
Keep up
  to date granddad.
 
  However what basic doesn't have is a portable language definition.

 May you could give us an idea of the current state of basic affairs
then by
 translating the following example snippet:

 It's me wrote:

  I saw this code from an earlier post:
 
  lst1 = [ab, ac, ba, bb, bc]
  lst2 = [ac, ab, bd, cb, bb]
  dct1 = dict.fromkeys(lst1) # -- I'll assume lst2 was intended.
  print [x for x in lst1 if x not in dct1]
  print [x for x in lst1 if x in dct1]
 
  It's simply remarkable for somebody to be able to do it so cleanly
(and so
  obviously) - out of the box, if you may.
 
  Sure, you can do it in Basic.  Ur...sure?  Yes, sure...

In Microsoft QBasic (1987), this could be written as:

DECLARE FUNCTION INARRAY% (ARR() AS STRING, X AS STRING)

DIM LST1(4) AS STRING
DIM LST2(4) AS STRING
DIM I AS INTEGER

FOR I = 0 TO UBOUND(LST1)
READ LST1(I)
NEXT

FOR I = 0 TO UBOUND(LST2)
READ LST2(I)
NEXT

' Print the elements of LST1 that are NOT in LST2
FOR I = 0 TO UBOUND(LST1)
IF INARRAY(LST2(), LST1(I)) = 0 THEN PRINT LST1(I);  ;
NEXT
PRINT

' Print the elements of LST1 that are in LST2
FOR I = 0 TO UBOUND(LST1)
IF INARRAY(LST2(), LST1(I)) = 1 THEN PRINT LST1(I);  ;
NEXT
PRINT

' Elements of LST1
DATA AB, AC, BA, BB, BC
' Elements of LST2
DATA AC, AB, BD, CB, BB

FUNCTION INARRAY% (ARR() AS STRING, X AS STRING)
' Return 1 if X in ARR, 0 otherwise
DIM I AS INTEGER
FOR I = LBOUND(ARR) TO UBOUND(ARR)
IF X = ARR(I) THEN
INARRAY = 1
EXIT FUNCTION
  END IF
   NEXT
   INARRAY = 0
END FUNCTION

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Re: BASIC vs Python

Adam DePrince [EMAIL PROTECTED] writes:
 On Fri, 2004-12-17 at 12:52, Mike Meyer wrote:
 Peter Hickman [EMAIL PROTECTED] writes:
  Basic has progressed much since you last looked at it, time to update
  your facts. Basic has recursion, it compiles to native code, it has
  objects, can be event driven and everything else you would expect of a
  language.
 What you describe isn't everything that I'd expect of a language. 
 Again, this is what I meant when I suggested that making basic your
 native language limits your horizon.

 1. First class functions
 2. Full functional programming support ala Standard ML
 3. Portability
 4. Elegance

Oddly enough, my second most favorite language (after Python) is
Eiffel. No first class functions. They do have a first-class
function-like object called an agent. But to use a standard method as
an agent, you have to wrap it.

Portability for the compiler I use is probably better than Python, as
they try very hard to stick to ANSI C, and not use Posix features.

Elegance - definitely more elegant than Python. There's a sound,
logical reason for every feature of the language, and the reasoning is
to help build robust, reliable code.

The problem is, the only compiler that runs in my environment to date
is missing most of the OS interfaces needed to do serious work. And
the garbage collector sucks rocks. It's still a joy to write small
programs in, but I can't use it for real work.

 Lastly, Mike, please refrain from argumentum ad hominem.  You never
 know where life will bring you.  Wouldn't it suck to find your dream
 job, only to meet Granddad at the interview?

The attributions got screwed up. I'm Mike - and I didn't call anyone
granddad, I was called granddad. My oldest is a bit young to have kids
yet.

  mike
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Re: A completely silly question

Steven Bethard [EMAIL PROTECTED] writes:

 Amir Dekel wrote:
 What I need from the program is to wait for a single character
 input, something like while(getchar()) in C. All those Python
 modules don't make much sence to me...

 sys.stdin.read(1)

That doesn't do what he wants, because it doesn't return until you hit
a newline.

The answer is system dependent. Or you can use massive overkill and
get curses, but if you're on windows you'll have to use a third party
curses package, and maybe wrap it


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better lambda support in the future?

2004-12-17 Thread Jason Zheng

I'm wondering why python still has limited lambda support. What's 
stopping the developers of python to support more lisp-like lambda function?
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Re: A completely silly question

2004-12-17 Thread wes weston

Amir Dekel wrote:
Harlin Seritt wrote:
Simple, Simple, Simple:
Var = raw_input(Some prompting text here: )
Frans Englich wrote:
 
  See sys.stdin
 
What I need from the program is to wait for a single character input, 
something like while(getchar()) in C. All those Python modules don't 
make much sence to me...

Amir
Amir,
 import tkSimpleDialog
 ch = tkSimpleDialog.askstring(,ch?)
wes
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Re: A completely silly question

2004-12-17 Thread marco

Amir Dekel wrote:
What I need from the program is to wait for a single character input, 
something like while(getchar()) in C. All those Python modules don't 
make much sence to me...
Take a look at Alan Gauld's Learning to Program
(http://www.freenetpages.co.uk/hp/alan.gauld/)
in the section Event Driven programming
Hope it helps
Marco
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Re: A completely silly question

Mike Meyer wrote:
That doesn't do what he wants, because it doesn't return until you hit
a newline.
Are you sure that's not just an artifact of how your terminal buffers 
data for sys.stdin?

$ cat temp.py
import sys
char = sys.stdin.read(1)
while char:
print char
char = sys.stdin.read(1)
$ cat temp.txt
abc
def
$ python temp.py  temp.txt
a
b
c
d
e
f
Of course if the intent is to have this work with terminal input, then 
yes, sys.stdin.read(1) is probably not going to do the right thing...

Steve
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Re: better lambda support in the future?

2004-12-17 Thread elbertlev

Lambda functions will become obsolette in the nearest future. This is
the PLAN.

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Re: BASIC vs Python

2004-12-17 Thread not [quite] more i squared

Adam DePrince wrote:
Given the hardware constraints of the early 1980s, which
language do you think should have been used instead of BASIC?

Lisp
Forth
Exactly my pick
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Re: Create linear spaced vector?

2004-12-17 Thread kjmacken

John,

Thanks for the heads up RE: scipy, I will keep my eyes on the
developments.

Also, thanks for the info:

[quote]
that the matplotlib.mlab package (where linspace and others functions
reside) do not require any extension code and can be reused anywhere
[/quote]

I was able to get these modules into my site-packages directory, and
make use of what is there.

Cheers,

kjm

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Re: better lambda support in the future?

Steven Bethard wrote:

 Even if you could settle the syntax issue, once you've decided that you 
 really do need a true 
 block in an anonymous function, you're not really saving much space by not 
 declaring it:

 def f(*args):
 # body line 1
 # body line 2
 # ...
 # body line N
 x = func or f

 v.s.

 x = func or lambda *args:
 # body line 1
 # body line 2
 # ...
 # body line N

you meant:

def x(*args):
# body line 1
# body line 2
# ...
# body line N

v.s.

x = func or lambda *args:
# body line 1
# body line 2
# ...
# body line N

right?

/F 



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Re: A completely silly question

Mike Meyer wrote:
Hmm. That tells me he's probably on a Windows box, so my unix solution
wouldn't do him much good.
Yes, Windows...too bad
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Re: BASIC vs Python

not [quite] more i squared [EMAIL PROTECTED] writes:

 Adam DePrince wrote:

Given the hardware constraints of the early 1980s, which
language do you think should have been used instead of BASIC?
 Lisp
 Forth
 Exactly my pick

Logo (my pick) has been called Lisp without the parenthesis. It has
the advantage of using standard algebraic notation for formulas,
instead of operator post or pre.

mike
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Re: Why are tuples immutable?

2004-12-17 Thread John Roth

I came in on this thread a bit late. The strictly
pragmatic answer to the question in the
header should be obvious.
If tuples were mutable, then there would be
no difference between tuples and lists, so
there would be no need for tuples.
Whether you think an immutable list is
worth while is a different question.
John Roth
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expression form of one-to-many dict?

So I end up writing code like this a fair bit:
map = {}
for key, value in sequence:
map.setdefault(key, []).append(value)
This code basically constructs a one-to-many mapping -- each value that 
a key occurs with is stored in the list for that key.

This code's fine, and seems pretty simple, but thanks to generator 
expressions, I'm getting kinda spoiled. ;)  I like being able to do 
something like the following for one-to-one mappings:

dict(sequence)
or a more likely scenario for me:
dict((get_key(item), get_value(item) for item in sequence)
The point here is that there's a simple sequence or GE that I can throw 
to the dict constructor that spits out a dict with my one-to-one mapping.

Is there a similar expression form that would spit out my one-to-many 
mapping?

Steve
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Re: better lambda support in the future?

2004-12-17 Thread Michael DeHaan

True enough, but suppose you want a hash of anonymous functions as
opposed to just a lexical?   This is where lambas are nice to have.  
Totally agreed about a small use here and there, but they do have some
use in dispatch tables, as they are a lot easier to read sometimes
than very long case statements.Of course, this would require
multi-line lambdas to exist...

--Michael

 I assume that the point you were trying to make is that:
 
 def f(*args):
  return expr
 
 is equivalent to
 
 f = lambda *args: expr
 
 ?
 
 Steve
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Re: expression form of one-to-many dict?

2004-12-17 Thread Tim Peters

[Steven Bethard]
 So I end up writing code like this a fair bit:

 map = {}
 for key, value in sequence:
 map.setdefault(key, []).append(value)

 This code basically constructs a one-to-many mapping -- each
 value that a key occurs with is stored in the list for that key.

 This code's fine, and seems pretty simple, but thanks to generator
 expressions, I'm getting kinda spoiled. ;)  I like being able to do
 something like the following for one-to-one mappings:

 dict(sequence)

 or a more likely scenario for me:

 dict((get_key(item), get_value(item) for item in sequence)

 The point here is that there's a simple sequence or GE that I can
 throw to the dict constructor that spits out a dict with my one-to-
 one mapping.

It's a simple sequence because it's a simple task.  It's even simpler
than perhaps it should be, since it arbitrarily decides that, if
more than one instance of some key is seen, it will only remember the
value associated with the last instance of that key.

 Is there a similar expression form that would spit out my one-to-
 manymapping?

There's a straightforward one-liner in 2.4 (but not notably concise),
if your keys are totally ordered:

from itertools import groupby
d = dict((k, map(get_value, g))
for k, g in groupby(sorted(sequence, key=get_key),
   key=get_key))

The real purpose of that is to increase your appreciation for your
original spelling 0.2 wink.
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Re: better lambda support in the future?

Steven Bethard wrote:

 You're welcome to name the function whatever you want -- notice in my example 
 that the function is 
 used in the statement:

 x = func or f

 If you'd prefer the statement to read:

 x = func or x

 that's also fine.  Depends on what exactly 'x' is, and whether or not it 
 really makes sense for 
 the function I called 'f' to have the same name as the variable called 'x'.  
 It certainly may, but 
 since I wasn't giving real code, I didn't want to commit to that.

if you write def f, f is a variable, just like x.  def is an assignment
statement.

I'm not sure what func is supposed to be in your examples...

 I assume that the point you were trying to make is that:

 def f(*args):
 return expr

 is equivalent to

 f = lambda *args: expr

 ?

 def f():
... return 1+2
...
 g = lambda: 1 + 2
 type(f)
type 'function'
 type(g)
type 'function'

 import dis
 dis.dis(f)
  2   0 LOAD_CONST   1 (1)
  3 LOAD_CONST   2 (2)
  6 BINARY_ADD
  7 RETURN_VALUE
 dis.dis(g)
  1   0 LOAD_CONST   1 (1)
  3 LOAD_CONST   2 (2)
  6 BINARY_ADD
  7 RETURN_VALUE

 dir(f)
['__call__', '__class__', '__delattr__', '__dict__', '__doc__', '__get__', '__ge
tattribute__', '__hash__', '__init__', '__module__', '__name__', '__new__', '__r
educe__', '__reduce_ex__', '__repr__', '__setattr__', '__str__', 'func_closure',
 'func_code', 'func_defaults', 'func_dict', 'func_doc', 'func_globals', 'func_na
me']
 dir(g)
['__call__', '__class__', '__delattr__', '__dict__', '__doc__', '__get__', '__ge
tattribute__', '__hash__', '__init__', '__module__', '__name__', '__new__', '__r
educe__', '__reduce_ex__', '__repr__', '__setattr__', '__str__', 'func_closure',
 'func_code', 'func_defaults', 'func_dict', 'func_doc', 'func_globals', 'func_na
me']

 f.func_name
'f'
 g.func_name
'lambda'

/F 



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Re: Troubleshooting: re.finditer() creates object even when nomatch found

Chris Lasher wrote:

 That's odd that there's no built-in method to do this. It seems like
 it would be a common task.

if you do this a lot, maybe you shouldn't use finditer?  iterators are
designed to give you the next item (if any) when you're ready to deal
with it...  if that's not what you want, you can use findall, search loops,
scanner objects, etc.  or you can implement a standard iterate ahead
loop.

what's your use case?

/F 



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Re: better lambda support in the future?