In linear time, find the maximum sum of all possible contiguous subarrays

[Gribouillis]

A new version for python >= 3.8

from operator import add, sub
from itertools import accumulate, tee

def gribmax2(iterable):
    s, t = tee(accumulate(iterable, add, initial=0))
    return max(map(sub, s, accumulate(t, min)))

It seems to agree with Deanhystad's version on 100000 arrays of length 100 with values in the range(-1000, 1000).

It took me a while to reach this quintessence of a function. I hope it will become a must in interviews from now on!