How to add sums of lists in python

Question

num_list_1 = [1,2,3,4]

sum of num_list_1 = 10

num_list_2 = [5,6,7,8]

sum of num_list_2 = 26

how would I be able to sum together num_list_1 and num_list_2.

I've tried doing it myself however as it is a list it wont let me concatenate them.

Answer 1

Get the sum of each list individually, and then sum the both scalar values to get the total_sum:

In [1733]: num_list_1 = [1,2,3,4]

In [1734]: num_list_2 = [5,6,7,8]

In [1737]: sum(num_list_1) + sum(num_list_2)
Out[1737]: 36

Answer 2

You could sum the concatenation of the two lists:

sum(num_list_1+num_list_2)

This is what I get using the python console:

>>>num_list_1 = [1,2,3,4]
>>>num_list_2 = [5,6,7,8]
>>>sum(num_list_1+num_list_2)
>>>36

Or you could just sum the sums:

sum(num_list_1) + sum(num_list_2)

which leads to the same output but in a probably faster way:

>>>num_list_1 = [1,2,3,4]
>>>num_list_2 = [5,6,7,8]
>>>sum(num_list_1) + sum(num_list_2)
>>>36

Answer 3

if you have several lists (more than 2) you could sum the sums by applying map to the results:

sum(map(sum,(num_list_1,num_list_2)))

Answer 4

+ acts as concatenating in case of lists, so sum(num_list_1 + num_list_2) will help

Answer 5

First Define both lists

num_list_1 = [1,2,3,4]
num_list_2 = [5,6,7,8]

then use Sum() For Both list

print(sum(num_list_1) + sum (num_list_2))

Also You Can Do This :

print(sum(num_list_1+ num_list_2))

Answer 6

You can use:

>>> num_list_1 = [1,2,3,4]
>>> num_list_2 = [5,6,7,8]
>>> sum(num_list_1+num_list_2)
>>> 36

Answer 7

sum takes an iterable, so you can use itertools.chain to chain your lists and feed the resulting iterable to sum:

from itertools import chain

num_list_1 = [1,2,3,4]
num_list_2 = [5,6,7,8]

res = sum(chain(num_list_1, num_list_2))  # 36