python assign values to list elements in loop

Question

Is this a valid python behavior? I would think that the end result should be [0,0,0] and the id() function should return identical values each iteration. How to make it pyth

Answer 1

Yes, the output you got is the ordinary Python behavior. Assigning a new value to foo will change foo's id, and not change the values stored in bar.

If you just want a list of zeroes, you can do:

bar = [0] * len(bar)

If you want to do some more complicated logic, where the new assignment depends on the old value, you can use a list comprehension:

bar = [x * 2 for x in bar]

Or you can use map:

def double(x):
    return x * 2

bar = map(double, bar)