List Length¶

As with strings, the function len returns the length of a list (the number of items in the list). However, since lists can have items which are themselves lists, it important to note that len only returns the top-most length. In other words, sublists are considered to be a single item when counting the length of the list.

alist =  ["hello", 2.0, 5, [10, 20]]
print(len(alist))
print(len(['spam!', 1, ['Brie', 'Roquefort', 'Pol le Veq'], [1, 2, 3]]))

(chp09_01a)

Check your understanding

list-3-1: What is printed by the following statements?

alist = [3, 67, "cat", 3.14, False]
print(len(alist))

list-3-2: What is printed by the following statements?

alist = [3, 67, "cat", [56, 57, "dog"], [ ], 3.14, False]
print(len(alist))