__cmp__ method

[JH]

Hi

Can anyone explain to me why the following codes do not work? I want to
try out using __cmp__ method to change the sorting order. I subclass
the str and override the __cmp__ method so the strings can be sorted by
the lengh. I expect the shortest string should be in the front. Thanks

>>> class myStr(str):
def __init__(self, s):
str.__init__(self, s) # Ensure super class is initialized
def __cmp__(self, other):
return cmp(len(self), len(other))

>>> a = myStr('abc')
>>> b = myStr('Personal')
>>> c = myStr('Personal firewall')
>>> sorted([c, b, a])
['Personal', 'Personal firewall', 'abc']
>>>

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Regular Expression pattern group

[JH]

Hi

I am a fussy learner. Could someone explain to me why the following
inconsistency exists between methods? How can it be justified if it is
considered all right?

There are three groups in pattern. However, match object shows 3 groups
in collection, but group has to be indexed from one because the
m.group(0) is the implicit group for whole pattern.

Are these just some things to remember? "Group counting is from one".

>>> p = sre.compile('abc(.(.).)d(ef)')
>>> s
'xxxabc???defxxx'
>>> m = p.search(s)
>>> m.groups()
('???', '?', 'ef')
>>> m.group(0)
'abc???def'
>>> m.group(1)
'???'
>>> m.group(2)
'?'
>>> m.group(3)
'ef'
>>> m.group(4)

Traceback (most recent call last):
  File "", line 1, in -toplevel-
m.group(4)
IndexError: no such group
>>> p.findall(s)
[('???', '?', 'ef')]
>>>

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Is type object an instance or class?

[JH]

Hi

I found that a type/class are both a subclass and a instance of base
type "object".

It conflicts to my understanding that:

1.) a type/class object is created from class statement
2.) a instance is created by "calling" a class object.

A object should not be both a class and an instance at the same time.

Further I found out there is a special type call "type" that is a
subclass of base type "object". All other types are instances of this
type.  Even base type "object" is an instance of this special type.

What is role of this type "type" in object creation?  Could someone
there straighten this concept a little?

For example (Python2.5):

>>> issubclass(int, object)
True
>>> isinstance(int, object)
True
>>> print type(int)

>>> isinstance(int, type)
True
>>> issubclass(int, type)
False
>>> issubclass(type, object)
True
>>> isinstance(type, object)
True
>>> isinstance(object, type)
True
>>>

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Re: how to get the path of a module (myself) ?

[jh]

Stef Mientki  gmail.com> writes:
> I don't seem to have pkg_utils,
> only pkgutil, which doesn't have an apropiate function.
> 
> But I found another way, don't know if that's reliable:
> import inspect
> print inspect.currentframe().f_code.co_filenameE

Eeek.

> head -999 foo/*
==> foo/__init__.py <==
import pkg_resources
print pkg_resources.resource_string(__name__, "bar")

==> foo/bar <==
bar

> python -c "import foo"
bar

Make a "def load_resource" from that print line and you're done.

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Re: Python IDE

[David JH]

On the subject can somebody here who uses SPE (or just has some
python knowledge) help me out with the installation process?  I tried
following http://spe.pycs.net/extra/manual/manual.html#windows but end
up with the error:


python /c/system/python24/Lib/site-packages/_spe/winInstall.py
Traceback (most recent call last):
File "/c/system/python24/Lib/site-packages/_spe/winInstall.py", line
1, in ?
import info
File "/c/system/python24/Lib/site-packages/_spe/info.py", line 1, in
?
import os,sys,sm.osx
ImportError: No module named sm.osx


interestingly enough there is an osx.py in
PYTHON_DIR/Lib/site-packages/sm so I figure I may just have python
configured poorly somehow.  Any ideas on where I should look?

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Re: Python IDE

[David JH]

On the subject can somebody here who uses SPE (or just has some
python knowledge) help me out with the installation process?  I tried
following http://spe.pycs.net/extra/manual/manual.html#windows but end
up with the error:


python /c/system/python24/Lib/site-packages/_spe/winInstall.py
Traceback (most recent call last):
File "/c/system/python24/Lib/site-packages/_spe/winInstall.py", line
1, in ?
import info
File "/c/system/python24/Lib/site-packages/_spe/info.py", line 1, in
?
import os,sys,sm.osx
ImportError: No module named sm.osx


interestingly enough there is an osx.py in
PYTHON_DIR/Lib/site-packages/sm so I figure I may just have python
configured poorly somehow.  Any ideas on where I should look?

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