Iterating package's module list

[ischenko at gmail.com]

Hi,

I'm trying to find all modules that contain doctests and execute them
(using DocTestSuite). The problem is how to iterate (programmatically)
through the package's modules.

>>> import M
>>> inspect.getmembers(M, inspect.ismodule)
[]

Iterating through the source files (via glob) does not help either:

>>> __import__('M.foobar')
<module 'M' from 'M\__init__.pyc'>

See, individual modules points to the base package, not to the module
itself.

How can I iterate through the modules that comprise a Python package?