Listing modules from all installed packages

[88888 Dihedral]

Carlos Nepomuceno於 2013年6月9日星期日UTC+8下午1時23分15秒寫道：
> print '\n'.join([re.findall("from '(.*)'",str(v))[0] for k,v in sys.modules.items() if str(v).find('from')>-1])
> 
> 
> 
> > Date: Sat, 8 Jun 2013 21:30:48 -0700
> > Subject: Listing modules from all installed packages
> > From: jph... at gmail.com
> > To: pytho... at python.org
> > 
> > Hi,
> > 
> > I'm trying to write a function that programmatically obtains and returns the exact location of all first-level modules for all installed packages.
> > 
> > For example, if the packages named 'django' and 'django-debug-toolbar' are installed, I'd like this function to return something like:
> > >>> installed_modules()
> > /Users/my_user/.virtualenvs/my_venv/lib/python2.6/site-packages/django
> > /Users/my_user/.virtualenvs/my_venv/src/debug_toolbar
> > 
> > That is, this function needs to consider all installed packages, including those that have been installed in "edit" mode (i.e. in the src/ folder). Note also that the main module for the 'django-debug-toolbar' is in fact named 'debug_toolbar'.
> > 
> > So far the closest I've been to retrieving the list of first-level modules is as follows:
> > 
> >     import os
> >     import pkg_resources
> >     import setuptools
> > 
> >     pkgs = set()
> > 
> >     for dist in pkg_resources.working_set:
> >         if os.path.isdir(dist.location):
> >             for pkg in setuptools.find_packages(dist.location):
> >                 if '.' not in pkg:
> >                     pkgs.add(pkg)
> > 
> > The idea is then to loop through that list of modules, import them and get their exact locations by fetching their __file__ attribute values.
> > 
> > However, this feels very hackish and I don't think it's actually quite correct either. I'm sure there must be a better way. If possible I'd also like to avoid having to use setuptools.
> > 
> > Do you have any tips on how to achieve this?
> > 
> > Many thanks!
> > 
> > Julien
> > -- 
> > http://mail.python.org/mailman/listinfo/python-list

Please use a dictionary to store a tree first.
Then it is trivial to walk through all nodes of the tree.