pass_vars.py

#!/usr/bin/env python

## source available at: http://git.io/MYVymw


def try_to_change_list_contents(the_list):
    print 'got', the_list
    the_list.append('four')
    print 'changed to', the_list

outer_list = ['one', 'two', 'three']


print 'before, outer_list =', outer_list

try_to_change_list_contents(outer_list)

print 'after, outer_list =', outer_list