We can filter a list of items through one or a few loops for sure.

But sometimes, we may not need to write any loops. Cause there is a function named itertools.compress().

The itertools.compress() function returns an iterator that filters an iterable based on the values of a corresponding boolean mask.

For example, the following code selects the true leaders using the itertools.compress() function:

import itertools

leaders = ['Yang', 'Elon', 'Tim', 'Tom', 'Mark']

selector = [1, 1, 0, 0, 0]

print(list(itertools.compress(leaders, selector)))

# ['Yang', 'Elon']

The second argument, selector, works as a mask, we can also define it as follows:

selector = [True, True, False, False, False]