indices - Read For Learn

How to find all occurrences of an element in a list

You can use a list comprehension: The iterator enumerate(my_list) yields pairs (index, item) for each item in the list. Using i, x as loop variable target unpacks these pairs into the index i and the list item x. We filter down to all x that match our criterion, and select the indices i of these elements.

TypeError: list indices must be integers or slices, not list

This is a classic mistake. i in your case is already an element from array (i.e. another list), not an index of array (not an int), so You can check the Python tutorial. Also, try doing this: And see what you get! Also I would advise to stick to naming conventions: variables are normally lower-case (volume, not Volume). In this case i is misleading. row or elem would be much more suitable.