Python: "import posix" question

Question

If I import os module, I can run the following to infer the location of os.py

>>> import os
>>> print os.__file__
/usr/lib/python2.6/os.pyc

However, when I import posix, it does not have the __file__ attribute. Is it because it is implemented as a part of the python runtime, not as a standard library?

How can I find out more information like this using solely the python official documentation?

Answer 1

It's a C module. It can be either built into the Python binary or compiled as a shared library. In your case it is compiled in

The official docs say not to import it directly, and you should use the functionality provided via os

Answer 2

Run python interactively.

>>> import posix
>>> help(posix)

There's a lot of good stuff there.

FILE
    (built-in)