experimental implementation to native len method (do not use it.)

len2.py

#!/usr/bin/python3
from functools import reduce
from operator import add
from datetime import datetime
def countIter2(i):
    try:
        i.__next__()
    except StopIteration:
        return 0
    return 1 + countIter2(i)

def len2(l):
    return countIter2(l.__iter__())


def len3(l):
    return reduce(add, [1 for i in l])

if __name__ == '__main__':
    l = list(range(900))

    start = datetime.now()
    count = len(l)
    end = datetime.now()
    print('native(%d)'%count,str(end-start))

    start = datetime.now()
    count = len2(l)
    end = datetime.now()
    print('len2(%d)  '%count,str(end-start))

    start = datetime.now()
    count = len3(l)
    end = datetime.now()
    print('len3(%d)  '%count,str(end-start))

###########
# RESULTS #
###########
# native(900) 0:00:00.000041
# len2(900)   0:00:00.001202
# len3(900)   0:00:00.000176