Python: Function Output Result Not as Expected

Question

Greeting all, would like to seek for your advice on the encountered issue as the output is not as expected.

my code as below:

score = []
total = 0
def mark():
    counter = 1
    size = int(input("Please Enter The Number of Subjects in Semester: "))
    for cnt in range (size):
        value = int(input(f"Please Enter Mark of Subject {counter} : "))
        score.append(value)
        counter = counter + 1
    total = sum(score)

mark()
print(score)
print(total)

and the output is:

Please Enter The Number of Subjects in Semester: 2
Please Enter Mark of Subject 1 : 10
Please Enter Mark of Subject 2 : 10
[10, 10]
0

Question 1: How can I turn the print(total) output to be sum of the values in the list instead of 0 without using Global variable?

Question 2: Why the list can get append but the score not making the sum?

It is an issue of scope. You need to include the line ```global total``` inside your function. — sarartur, Feb 17 '21 at 06:35
Get used to passing parameters into functions and returning results: `return score, total`, and on the calling side: `score, total = mark()`. — deceze, Feb 17 '21 at 06:37
*"Why the list can get append but the score not making the sum?"* — Because you're *mutating* the list object, which remains the same list object, but you're *reassigning* variable `total`, which makes it a function-local variable entirely independent of the global variable of the same name. — deceze, Feb 17 '21 at 07:55

score 0 · Answer 1 · answered Feb 17 '21 at 06:36

Add

global total

as the first line of your function. As it is, the total in your function is a separate variable from the total outside. As an alternative, you might consider returning score and total from the function; as a rule, global variables are a Bad Idea.

Python: Function Output Result Not as Expected

1 Answers1