Question

Is it expected that nested variables in Python overlaps?
for example:

for i in range(1,10):
    x = [0xFF for i in range(6)]
    print(i)

what is the expected result (sequence) ?
With Python 2.7 I’m getting nine fives.

Answer 1

What you see is a side-effect of using list comprehensions.
The iterator variable inside the list comprehension is identical with the one of the for loop. This means that the iterator variable of the list comprehension is not local the expressions itself.

Example:

>>> [x for x in range(10)]
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
>>> print x
9

So both iterator variable names should be distinct.