Changing python list size during iteration. Is it okay?

hmm... for easier explanation, what happened here is

when you run for i in range(len(a)):

it will automatically run for i in range(5):

so it will not call the len function again and again for each loop

This is another example:

length=5
for i in range(length):
    length=2
    print(length)

the result is

2
2
2
2
2

Correct me if I am wrong, but I think most of for iteration (any language) is fixed since beginning, if you want to loop something that is not fixed, better use while

length=5
i=0
while i < length:
    length=2
    print(length)
    i+=1

The result

2
2