How does the len() function relate to index values for lists?



What is the relationship between the value returned by len() and the indexes which can be used to access elements of a list?


The len() function returns the number of items in a list. Since list indexes start at 0, the value of len() represents a value one larger than the last index. This means the valid indexes of a list are any number between 0 and len() - 1. The len() function is commonly used with the range() function. Since range() by default, returns a list from 0 to one less than the number passed, the len() of a list can be passed to range() to generate a valid list of indexes. This is shown in the example below.

examples = ['red', 'green', 'blue', 'orange']

# This will print 4 which is the number of elements in examples.

# This will return a list ([0, 1, 2, 3]) which provides indexes to the examples.
for color in range(len(examples)):