where is the 'itertools' file.

Question

import itertools
print itertools#ok

the code is ok

but i can't find the itertools file.

who can tell me where is the 'itertools file'

---

my code is run python2.5

import itertools
print itertools.__file__


Traceback (most recent call last):
  File "D:\zjm_code\mysite\zjmbooks\a.py", line 5, in <module>
    print itertools.__file__
AttributeError: 'module' object has no attribute '__file__'

Answer 1

try this

>>> import imp
>>> imp.find_module("itertools")

update: since yours is None, another go through a manual way. Do a sys.path

>>> import sys
>>> sys.path
['', '/usr/lib/python2.6/lib-dynload' ]

then depending on your system, use your system's search facility to find it. on my linux system

$ find /usr/lib/python2.6/lib-dynload -type f -iname "*itertools*"
/usr/lib/python2.6/lib-dynload/itertoolsmodule.so

OR, just search the entire system for the file with name "itertools".

Answer 2

>>> import itertools
>>> itertools.__file__
'/usr/lib64/python2.6/lib-dynload/itertools.so'

The fact that the filename ends with .so means it's an extension module written in C (rather than a normal Python module). If you want to take a look at the source code, download the Python source and look into Modules/itertoolsmodule.c (you can also view it in your browser at http://svn.python.org/view/python/trunk/Modules/itertoolsmodule.c?view=log).

Edit (as an answer to the comment below): it also works with Python 2.5:

Python 2.5.2 (r252:60911, Oct  5 2008, 19:29:17) 
[GCC 4.3.2] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import itertools
>>> itertools.__file__
'/usr/lib/python2.5/lib-dynload/itertools.so'

Answer 3

If you're looking for the source file (in C, of course), it's for example online here.