#!/usr/bin/env python

"""
   Parameters in Python are passed by value. 
   We need to have in mind the following:
    1- The parameter passed in is actually a reference to a 
       variable (but the reference is passed by value)
    2- Some data types are mutable, but others aren't
"""

# Example 2: List - a mutable type
#            A list parameter is passed by value, assigning 
#            a new list to it had no effect that the code 
#            outside the method could see. 
#            The list inisde the function is a copy of the 
#            original list reference, and we have a list pointing
#            to a new list, but there is no way to change where 
#            the original list pointed.

def try_to_change_list_reference(the_list):
    print 'got', the_list
    the_list = ['and', 'we', 'can', 'not', 'lie']
    print 'set to', the_list

outer_list = ['we', 'like', 'proper', 'English']

print 'before, outer_list =', outer_list
try_to_change_list_reference(outer_list)
print 'after, outer_list =', outer_list