Source: 📖 Effective Python item 36

itertools.takewhile

This function takes a function and an iterator as arguments, and returns items from the iterator until the function evaluated to False:

values = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
less_than_seven = lambda x: x < 7

it = itertools.takewhile(less_than_seven, values)
print(list(it))

>>>
[1, 2, 3, 4, 5, 6]