performance of list.remove(value) in Python 2.7

Question

Suppose a list contains a list of integers, if I call list.remove(100) to remove element with value 100, wondering if it is O(n) or O(logN) ? I thought it is O(n) , but not sure if Python 2.7 list has any internal optimizations to improve performance even further. Thanks.

regards, Lin

Answer 1

Removing an item from a list in Python is O(n) . This is because the underlying space in memory must be "shifted over" now that an element is missing. There are other implementations of lists, such as a linked list, that you could use in Python for constant time removal, but the built in List data structure is definitively O(n)