Some simple profiling.

profiling.py

import cProfile, pstats
import operator
import contextlib
from functools import reduce
from itertools import accumulate
import sys

def cumsum(num=0):
    """Loop based"""
    total = 0
    for n in range(0, num + 1):
        total = total + n

    return total

def cumsum2(num=0):
    """Reduced"""
    return reduce(operator.__add__, range(0, num + 1), 0)

def cumsum3(num=0):
    """Recursive"""
    if num == 0:
        return num

    return cumsum3(num - 1) + num

def cumsum4(num=0):
    """Memory hungry"""
    return list(accumulate(range(0, num + 1)))[-1]

@contextlib.contextmanager
def profile(sort_by=pstats.SortKey.CUMULATIVE):
    pr = cProfile.Profile()
    pr.enable()
    yield
    pr.disable()
    ps = pstats.Stats(pr).sort_stats(sort_by)
    ps.print_stats()

HIGH_WATERMARK = 10000 

with profile():
    print(cumsum(HIGH_WATERMARK))

with profile():
    print(cumsum2(HIGH_WATERMARK))

# high values (say > 10000) will likely cause segmentation faults
if HIGH_WATERMARK < 10000:
    sys.setrecursionlimit(HIGH_WATERMARK + 3)
    with profile():
        print(cumsum3(HIGH_WATERMARK))

with profile():
    print(cumsum4(HIGH_WATERMARK))