How to pop many items from list?-CodePudding

I want to pop certain items from my list. This is my code:

lst = [1,2,3,4,5,6,7,8,9]
popVal = [0, 5, 8]
for i in popVal:
    lst.pop(i)

The expected output should be [2,3,4,5,7,8] as index 0, 5 and 8 are removed from lst

However, I get a error:

Traceback (most recent call last):
  File "<stdin>", line 2, in <module>
IndexError: pop index out of range

And if I print my list, this is the output

[2, 3, 4, 5, 6, 8, 9]

CodePudding user response：

You should iterate through popVal backward and pop the last item first:

lst = [1, 2, 3, 4, 5, 6, 7, 8, 9]
popVal = [0, 5, 8]
for i in popVal[::-1]:
    lst.pop(i)

CodePudding user response：

Each time you pop an element, the list shrinks. As such, what used to be at index 8 for example, is now at index 3.

Assuming your list of popVal is strictly ascending, the following modified code would work

lst = [1,2,3,4,5,6,7,8,9]
popVal = [0, 5, 8]
for n, i in enumerate(popVal):
    lst.pop(i - n)

This ensures that as the list shrinks, the index to pop from shrinks accordingly as well.