Answer by Massimo for How do I get a list of locally installed Python modules?

There are many ideas, initially I am pondering on these two:

pip

cons: not always installed

help('modules')

cons: output to console; with broken modules (see ubuntu...) can segfault

I need an easy approach, using basic libraries and compatible with old python 2.x

And I see the light: listmodules.py

Hidden in the documentation source directory in 2.5 is a small script that lists all available modules for a Python installation.

Pros:

uses only imp, sys, os, re, time

designed to run on Python 1.5.2 and newer

the source code is really compact, so you can easy tinkering with it, for example to pass an exception list of buggy modules (don't try to import them)