why am I getting "local variable 'x' referenced before assignment"?

[wlsa]

Given an array of ints (as a list), print the sum of all the elements.
My code:

L=[1, 1, 1, 2]
x=0
def sum3(nums):
    for i in nums:
        x+=i
print(sum3(L))

How is x a local variable if I define it outside of the loop?

[Larz60+]

x is defined outside the scope of the function sum3.
Global variables are frowned upon, and there are better methods of doing this,
however adding global x as the first statement (before the if) will solve for now.

[wlsa]

What do you mean before the if?

[buran]

he meant for not if
however you don't want it to be global
just move the x = 0 line in the function.
Then you will face a new problem, because your function does not return anything, so it will return None and that's what you will get printed.... You need to fix this as well.

Note that this is not the best approach to sum elements of a list. There is built-in function that does the same

[ichabod801]

Note that this is not the best approach to sum elements of a list. There is built-in function that does the same

I think it's OP's homework assignment to recreate the built-in function.

[wlsa]

What is the built-in function for this?

[buran]

sum