Python idiom for iterating over changing list

Question

Is there a better (more obvious/idiomatic) way in python to write an equivalent of

index = 0
while index < len(some_list):
    do_some_stuff(some_list[index])         


        

Answer 1

You might break up the operations into two separate loops, and use a list comprehension for the second part.

for value in some_list:
    do_some_stuff(value)

some_list = [value for value in some_list if not delete_element(value)]

Another solution would be to iterate over a copy of the list, and use enumerate to keep track of the indices without having to maintain a counter by hand.

for index, value in enumerate(some_list[::-1]):
    do_some_stuff(value)
    if delete_element(value):
        del some_list[-index - 1]

You'd want to iterate backwards so you don't have to adjust index for the deleted elements.