Tirar um módulo python de contexto (from: http://stackoverflow.com/questions/1668223/how-to-de-import-a-python-module)

delete_modules.py

def delete_module(modname, paranoid=None):
    from sys import modules
    try:
        thismod = modules[modname]
    except KeyError:
        raise ValueError(modname)
    these_symbols = dir(thismod)
    if paranoid:
        try:
            paranoid[:]  # sequence support
        except:
            raise ValueError('must supply a finite list for paranoid')
        else:
            these_symbols = paranoid[:]
    del modules[modname]
    for mod in modules.values():
        try:
            delattr(mod, modname)
        except AttributeError:
            pass
        if paranoid:
            for symbol in these_symbols:
                if symbol[:2] == '__':  # ignore special symbols
                    continue
                try:
                    delattr(mod, symbol)
                except AttributeError:
                    pass


'''
>>> import sys
>>> import pymongo
>>> 'pymongo' in sys.modules.keys()
True
>>> delete_module('pymongo')
>>> 'pymongo' in sys.modules.keys()
False
'''