where is the 'itertools' file
<pre><code>import itertools
print itertools#ok
</code></pre>

<p>the code is ok</p>

<p>but i can't find the itertools file.</p>

<p>who can tell me where is the 'itertools file'</p>

<hr>

<p>my code is run python2.5</p>

<pre><code>import itertools
print itertools.__file__


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