Django python function

[hito koto]

Hello,

I don't know how can i do to change to write python function
I want to following code change to write python function　or change to write  recursive definition
>>> y = [10, 12, [13, [14, 9], 16], 7]
>>> z = copy.deepcopy(y)
>>> y
[10, 12, [13, [14, 9], 16], 7]
>>> z
[10, 12, [13, [14, 9], 16], 7]
>>> z[2][1][1]
9
>>> z[2][1][1] = 88
>>> z
[10, 12, [13, [14, 88], 16], 7]
[10, 12, [13, [14, 9], 16], 7]
>>>