Find which python modules are being imported

What's an easy way of finding all the python modules from a particular package that are being used in an application?

sys.modules is a dictionary mapping module names to modules. You can examine its keys to see imported modules.

See: http://docs.python.org/library/sys.html#sys.modules

You could use python -v, which will emit messages about every imported module:

$ echo 'print "hello world"' > helo.py
$ python -v helo.py
# installing zipimport hook
import zipimport # builtin
# installed zipimport hook
# /System/Library/Frameworks/Python.framework/Versions/2.5/lib/python2.5/site.pyc matches /System/Library/Frameworks/Python.framework/Versions/2.5/lib/python2.5/site.py
import site # precompiled from /System/Library/Frameworks/Python.framework/Versions/2.5/lib/python2.5/site.pyc
# /System/Library/Frameworks/Python.framework/Versions/2.5/lib/python2.5/os.pyc matches /System/Library/Frameworks/Python.framework/Versions/2.5/lib/python2.5/os.py
import os # precompiled from /System/Library/Frameworks/Python.framework/Versions/2.5/lib/python2.5/os.pyc
import posix # builtin
# /System/Library/Frameworks/Python.framework/Versions/2.5/lib/python2.5/posixpath.pyc matches /System/Library/Frameworks/Python.framework/Versions/2.5/lib/python2.5/posixpath.py
import posixpath # precompiled from /System/Library/Frameworks/Python.framework/Versions/2.5/lib/python2.5/posixpath.pyc

...and so on, and so forth. Of course you can later grep the modules of interest from among this large list!-)