list=[[10,12,22],[18,20,38],[32,35,67],[57,66,123],[103,121,224]] 

This is the list that I am looping through.

for i in range(len(list)):
    print(f"The sum of every 3rd element within each sub list is {sum(list[i][2])}

When I run this, the error message is:

TypeError: 'int' object is not iterable

Is this simply not possible to do or am I making a stupid mistake?
I am quite new to coding so apologies for what may seem like a very stupid question to some.

>Solution :

I’ll help you out. First don’t use python keywords as a variable name – so list is not good. Secondly I see so many people iterating over the range of the list and then referencing by index. This isn’t necessary.

l =[[10,12,22],[18,20,38],[32,35,67],[57,66,123],[103,121,224]]

How I often see it done

for i in range(len(l)):
    print(l[i][2])

How it probably should be done

for x in l:
    print(x[2])

And the answer you are looking for:

sum(x[2] for x in l)