pythonlistindexing

How to obtain the last index of a list?


Suppose I've the following list:

list1 = [1, 2, 33, 51]
                    ^
                    |
indices  0  1   2   3

How do I obtain the last index, which in this case would be 3, of that list?


Solution

  • len(list1)-1 is definitely the way to go, but if you absolutely need a list that has a function that returns the last index, you could create a class that inherits from list.

    class MyList(list):
        def last_index(self):
            return len(self)-1
    
    
    >>> l=MyList([1, 2, 33, 51])
    >>> l.last_index()
    3