In Python, what does the list method .append() do?

The .append() method in Python is specifically designed to add an item to the end of a list. When this method is called on a list, it takes a single argument, which is the item you want to add, and appends this item to the end of the list. This operation modifies the original list in place and does not return a new list.

For instance, if you have a list defined as my_list = [1, 2, 3] and you use my_list.append(4), the list will then be updated to [1, 2, 3, 4]. The capability to dynamically add elements to a list like this is one of Python's strengths, allowing for flexibility in how data is managed.

The other options describe actions that are not performed by the .append() method: removing an item from the list, inserting an item at a specific position, or returning the number of items in the list do not align with the functionality of the .append() method as designed in Python.