Passing multiple list in a function as *args gives a None result

Question

I try to pass lists in a function as args but the results give me a None in the end. Can you explain to me why?

list_1 = [1, 2, 4]
list_2 = [3, 4, 2]


def total_list(*args):
    for item in args:
        for i in item:
            print(i)


print(total_list(list_1, list_2))

Result:

1
2
4
3
4
2
None

score 2 · Answer 1 · answered May 11 '19 at 15:42

2

print(total_list(list_1, list_2))

You're also printing the return-value of the total_list function. Since you don't have any return statement, it evaluates to None. That's where the None is coming from.

answered May 11 '19 at 15:42

rdas

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score 1 · Answer 2 · answered May 11 '19 at 15:43

Since there is no return value of total_list function, which means the return value is None, when you call the total_list function inside print, it ends up printing None

Call the function outside print, and you will see what's happening

def total_list(*args):
    for item in args:
        for i in item:
            print(i)

list_1 = [1, 2, 4]
list_2 = [3, 4, 2]
total_list(list_1, list_2)

The output will be

Passing multiple list in a function as *args gives a None result

2 Answers2