The sum of the nested list without using the SUM function (exercise)

Question

Trying to write a function that takes the sum of each list and returns individual values ​​in a new single list. For instance,

[[2, 7, 6], [9, 5, 1], [4, 3, 8]] 

becomes

[15, 15, 15]

What I still have:

def row_sums(square):
    total_list = []
    total = 0
    for i in square:
        for j in i: 
            total += j
        total_list.append(total)
    return total_list    

But it just accumulates each list on top of each other, resulting in:

[15, 30, 45] 

I am not sure how to save the amounts for each list separately. The SUM function is not allowed here because it is an exercise on nested loops.

Thank.

Answer 1

You need to reset your counter totalbefore starting each of them. In addition, you do not need to declare it outside, because you will use it only inside.

def row_sums(square):
    total_list = []
    for i in square:
        total = 0
        for j in i: 
            total += j
        total_list.append(total)
    return total_list 

Answer 2

, total . sum = 0 :

def row_sums(square):
    total_list = []
    for i in square:
        total = 0
        for j in i: 
            total += j
        total_list.append(total)
    return total_list  

Answer 3

:

>>> list = [[2, 7, 6], [9, 5, 1], [4, 3, 8]] 
>>> import functools
>>> [functools.reduce(lambda x, y: x + y, sublist, 0) for sublist in list]
[15, 15, 15]

sum:)

functools.reduce .

: , [functools.reduce(int.__add__, sublist, 0) for sublist in list] ( , !)

Answer 4

.

def row_sums(square):
    total_list = []
    total = 0
    for i in square:
       for j in i: 
          total += j
       total_list.append(total)
       total = 0
    return total_list

Answer 5

, (, ):

def _notsum2(lists):
    per_yield = len(lists)
    total = 0
    for ind, next in enumerate(val for sublist in lists for val in sublist):
        if ind % per_yield == 0 and ind:
            yield total
            total = 0
        total += next
    yield total


if __name__ == '__main__':
    li = [[2, 7, 6], [9, 5, 1], [4, 3, 8]]
    print [g for g in _notsum2(li)]

Answer 6

map :

l=[[2, 7, 6], [9, 5, 1], [4, 3, 8]] 
a,b,c=[x for x in l]
map(lambda x,y,z:x+y+z, a,b,c)

Answer 7

[sum(i) for i in zip(*[[2, 7, 6], [9, 5, 1], [4, 3, 8]])]

bultin zip func - ,