dict_example.py

def foo(dict, n=2):
    if n == 0: return

    dict1 = dict

    dict[n] = n
    foo(dict, n - 1)

    dict2 = dict

    # At this point dict1 and dict2 point to same object
    # if n == 2 then 
    # dict, dict1, dict2 point to this
    # {
    # 	2: 2,
    #	1: 1
    # }