>>> person=['name',['savings',100]]
>>> hubby=person[:]
>>> wifey=list(person)
>>> [id(x) for x in person,hubby,wifey]
[3074051788L, 3074061740L, 3074061996L]
>>> [id(y) for x in person,hubby,wifey for y in x]
[3074319552L,3073979916L,3074319552L,3073979916L,3074319552L,3073979916L]
>>> hubby[0]='joe'
>>> wifey[0]='jane'
(['joe',['savings',100]],['jane',['savings',100]],['name',['savings',100]])
>>> hubby[1][1]=70
>>> hubby,wifey,person
(['joe',['savings',70]],['jane',['savings',70]],['name',['savings',70]])