Question

I am trying to get my function to take two arguments, and return their sum. Am I going about this the right way? This is what I have so far:

def my_sum(a, b):
    sum = a + b

def main():
    a = input(int("enter a number: ", a)
    b = input(int("enter a number: ", b)

    sum = a + b

    return sum
    print(" result: ", sum)

main()

Answer 1

So it looks good, but the main problem is that you aren’t actually calling your function 🙂 Once you get your two numbers, you can then make the call to your function (which you have properly set up):

def main():
    # When you assign variables here, make sure you are putting the int outside
    # You also don't need to reference the variable twice
    a = int(input("enter a number: "))
    b = int(input("enter a number: "))

    # Here is where your call goes (try to avoid using variable names that
    # are the same as Python keywords, such as sum)
    s = my_sum(a, b)

    print(" result: ", s)

Now, one other thing you’ll have to do is modify your function to return a value. You’re already almost there – just add a return (note that since you are just returning the sum of the two numbers, you don’t have to assign it to a variable):

def my_sum(a, b):
    return a + b

This now means that when you run s = my_sum(a, b), your function will return the sum of those two numbers and put them into s, which you can then print as you are doing.

One other minor thing – when you use the setup you are (with def main(), etc.), you usually want to call it like this:

if __name__ == '__main__':
    main()

At this stage, don’t worry too much about what it means, but it is a good habit to get into once you start getting into fun stuff like modules, etc. 🙂