What is the time complexity of popping elements from list in Python?

Question

I wonder what is the time complexity of pop method of list objects in Python (in CPython particulary). Also does the value of N for list.pop(N) affects the complexity?

Answer 1

It should be O(1) with L.pop(-1), and O(n) with L.pop(0)

see following example:

from timeit import timeit
if __name__ == "__main__":
    L = range(100000)
    print timeit("L.pop(0)",  setup="from __main__ import L", number=10000)
    L = range(100000)
    print timeit("L.pop(-1)", setup="from __main__ import L", number=10000)

>>> 0.291752411828
>>> 0.00161794329896