Detailed usage instructions for the SUM function in Python

#!/usr/bin/env python
#-*-coding:utf-8-*-

# The most common usage of sum calculates the summation and print of a sequence (
sum ([1, 2, 3]))
# 6

# sum The function prototype is sum (iterable, start), and can also give an initial value of
print (sum ([1, 2, 3], ten))
#

# Another comparison hack some usages, expand the 2-tier nested list
Iterable = [[1, 2], [3, 4], [5, 6], [7, 8]]]
start = [0]
print (SUM (iterable, start))
# [0, 1, 2, 3, 4, 5, 6,  7, 8]

# The SUM function is equivalent to the following procedure for an
element in iterable:
    start = = Element
print (start)
# [0, 1, 2, 3, 4, 5, 6, 7, 8]

# In fact, sum can be considered as a special case of reduce () from
functools import reduce from
operator import add
start = [ ]
print (Reduce (add, iterable, start))
# [1, 2, 3, 4, 5, 6, 7, 8]