<p>How do I learn where the source file for a given Python module is installed? Is the method different on Windows than on Linux?</p>

<p>I'm trying to look for the source of the <code>datetime</code> module in particular, but I'm interested in a more general answer as well.</p>

The
```
sys.path
```
list contains the list of directories which will be searched for modules at runtime:
```
```
python -v
>>> import sys
>>> sys.path
['', '/usr/local/lib/python25.zip', '/usr/local/lib/python2.5', ... ]
```
```