Why is list.remove only removing every second item?

Question

In my Python 2.7.2 IDLE interpreter:

>>> mylist = [1, 2, 3, 4, 5]
>>> for item in mylist:
        mylist.remove(item)

>>> mylist
[2,          


        

Answer 1

Problem is that you are altering the list while iterating on it. Use a list comprehension instead:

mylist = [1, 2, 3, 4, 5]
mylist = [x for x in mylist if condition(x)]