Quick Python: Length of Iterables

Brandon Rozek

March 25, 2020

I wanted to find the length of what I know is a finite iterable. Normally you would think of using the len function but it does not work in this case. Al Hoo on StackOverflow shared a quick snippet to calculate this.

from functools import reduce

def ilen(iterable):
    return reduce(lambda sum, element: sum + 1, iterable, 0)

This also turns out to be memory efficient since we are only loading in one object into memory from the iterable at a time.