Sum Numbers Of Each Row Of A Matrix Python

lista = [[1,2,3],[4,5,6],[7,8,9]] print(lista) def filas(lista): res=[] for elemento in lista: x = sum(lista[elemento]) res.append(x) print(res) I n

Solution 1:

The issue you are having, is that you are already iterating over the elements so it is unnecessary to use it as an index:

x = sum(elemento)

It is generally considered bad form but to iterate over indexes you would use:

for i inrange(len(lista)):
    x = sum(lista[i])

However, without introducing any other modules, you can use map() or a simple list comprehension:

>>>res = list(map(sum, lista))   # You don't need `list()` in Py2>>>print(res)
[6, 15, 24]

Or

>>>res = [sum(e) for e in lista]>>>print(res)
[6, 15, 24]

Solution 2:

Do you want like this?

lista = [[1,2,3],[4,5,6],[7,8,9]]print(lista)

def filas(lista):
    summed_list = [sum(i) for i in lista]
    print(summed_list)
filas(lista)

Solution 3:

You can do this easly, with dot product. This is much faster than any loop.

lista = np.float32([[1,2,3],[4,5,6],[7,8,9]])
vet_one = np.ones(len(lista))
vet_sum = lista.dot(vet_one)

Solution 4:

Is this what you want to do?

deffilas(lista):
    res=[]
    for elemento in lista:
        x = sum(elemento) # <- change this line.
        res.append(x)
    print(res)