to get sum of the sub lists

Question

Hi there,

I tried to perform a code which divide the given list into three. And then get sum of each part into a new list (without build in).

For example;

given list = [1,2,3,4,5,6,7,8,9]
output=[6,15,24]

My code:

def y(x):
    t=len(x)
    z=0
    f=0
    sum=[]
    if t%3!=0:
        return "can not be divided into 3 parts"
    else:
        for i in range(z,t,int(t/3)):
            z=i
            r=x[z:z+int(t/3)]
            for j in r:
                f=+j
            sum.append (f)

    return sum

y([1,2,3,4,5,6])

i could divide the list into three part. However i can not get the true result for sum of each part.

Can anyone help me?

Answer 1

Hercule Poirot , nice code. Abhay , you have been faster than me, but i found the same issues. So I have no choice but to improve something else.
The code is working with 3 slices in a loop, then calculating the sum of each slice. I thought it would be nice to shorten this by using the sum function:

lst = [1,2,3,4,5,6,7,8,9]
def y(x):
t=len(x)
sum_=[]
if t%3!=0:
return "can not be divided into 3 parts"
else:
for i in range(0,t,int(t/3)):
sum_.append (sum(x[i:i+int(t/3)]))
return sum_

print(y(lst))

Answer 2

here it is,

def y(x):
t=len(x)
z=0
f=0
sum=[]
if t%3!=0:
return "can not be divided into 3 parts"
else:
for i in range(z,t,int(t/3)):
z=i
r=x[z:z+int(t/3)]
print(r)
for j in r:
print(j)
f+=j
sum.append(f)
f=0
return sum

print(y([1,2,3,4,5,6]))

Answer 3

Hercule Poirot for j in r:
Loops over first two numbers and add to f so f has a value of 3 now ,if you won't set f to 0 again it will be keep adding new values from for j in r: loop to 3 so instead of 3,7 you will get 3,10 and so on

Answer 4

ty a lot for your great help. i really appricate it. :)

Answer 5

ty a lot Abhay. I m now in phyton and also coding. could you explain what iş the role of f=0 in the code?

Answer 6

Lothar nice approach and seems like we don't even need sum variable as well and can use list comprehension instead ,

lst = [1,2,3,4,5,6,7,8,9]
def y(x):
t=len(x)
if t%3!=0:
return "can not be divided into 3 parts"
else:
return([sum(x[i:i+int(t/3)]) for i in range(0,t,int(t/3))])

print(y(lst))

Answer 7

ty Lothar for your help. :)