Same variable name for different values in nested loops.

Question

This code is perfectly valid Python

x=[[1,2,3,4], [11,22,33,44]]
for e in x:
    for e in e:
        print e

Can someone please tell me why

Answer 1

Because second e binds after first e evaluates to list. So, all other iteration steps take items not from variable, but from list. For example, in next code reassinging to e has no effect on iteration:

for e in x:
    for i in e:
        print i
        e = [8, 8, 8]