41 – Longest and shortest

The built-ins max and min have a keyword argument key that lets you change the frame of reference for comparisons.

If you then use functools.partial to attach another function to key, you essentially build new functions just like LEGOs.

My two favourite examples:

1. max + key=len builds the function longest; and

2. min + key=len builds the function shortest.

from functools import partial

longest = partial(max, key=len)
shortest = partial(min, key=len)

words = "This is a truly extraordinary sentence".split()
print(longest(words))  # extraordinary
print(shortest(words))  # a