gistfile1.py

# Randoms.py:

import random
import hahaha
import hihihi
print "Hello, this is the end of the file"

# check_module.py

In [1]: from modulefinder import ModuleFinder
In [2]: finder = ModuleFinder()
In [3]: finder.run_script('Randoms.py')
In [4]: print '\n'.join(finder.badmodules.iterkeys())
riscospath
os2
_sha512
riscos
_emx_link
_subprocess
ce
_md5
_sha256
_sha
hihihi
org.python.core
hahaha
riscosenviron
nt
msvcrt
os.path

# Note you can also use finder.any_missing, according to help(finder.any_missing)

In [11]: finder.any_missing ?
Type:       instancemethod
String Form:<bound method ModuleFinder.any_missing of <modulefinder.ModuleFinder instance at 0x20a09e0>>
File:       /usr/lib/python2.7/modulefinder.py
Definition: finder.any_missing(self)
Docstring:
Return a list of modules that appear to be missing. Use
any_missing_maybe() if you want to know which modules are
certain to be missing, and which *may* be missing.

In [12]: finder.any_missing()
Out[12]: 
['_emx_link',
 '_md5',
 '_sha',
 '_sha256',
 '_sha512',
 '_subprocess',
 'ce',
 'hahaha',
 'hihihi',
 'msvcrt',
 'nt',
 'org.python.core',
 'os.path',
 'os2',
 'riscos',
 'riscosenviron',
 'riscospath']