[Distutils] how can I egt the packages and modules in a distribution?

[P.J. Eby]

At 06:29 PM 8/19/2010 +0100, Chris Withers wrote:
>Hi All,
>
>Given a distribution name (ie: one of those things setuptools uses, 
>'name' parameter to setup.py's setup call, etc) of a dsitrbution 
>that has been installed with easy_install, buildout, pip, etc, how 
>can I find out what python packages (ie: dotted names that I can 
>import) are provided by that package?
>
>I'm trying to write a scanner than looks for SQLAlchemy table 
>objects and it would be great to be able to pass a distribution name 
>rather than a set of dotted package names...

get_distribution('projectname').get_metadata('top_level.txt').splitlines() 
will return you a list of top-level package or module names provided 
by the package.

Subpackages you'll have to find yourself; the pkgutil module in 2.5+ 
has a walk_packages() that might be helpful.

(Note that if there are packages installed in "flat" form (e.g. 
pip-installed or system-installed), you may see overlapping packages 
in the same directory, so simply walking packages in a distribution 
object's base directory may include packages and modules from another project.)