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Python

Posted by behar
behar
10,800 Points

returning something to a function?

So say i have the following function:

def add():
    print("test")

I can call that function by doing add() and it will just print the test

Now say that i want to return something to that function:

def add2():
    print("test")
    return 2 + 2

While still being able to just call the function and get the test, how would i find what i returned to the function, that is the 2+2??

1 Answer

Jennifer Nordell
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STAFF
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Jennifer Nordell
Treehouse Teacher
Jennifer Nordell
.a{fill-rule:evenodd;}techdegree
Jennifer Nordell
Treehouse Teacher

Hi there! You don't return to a function. You return from a function.

And you understand how to run a function, so that's good. So let's take a look at your example, but let's remove the print of the "test":

def add2():
    return 2 + 2

This example function will only ever return the number 4. That number is returned to the call site where you tell the function to execute. So if you had this:

def add2():
    return 2 + 2

print(add2())

The add2() would return a 4 and that is what would be printed.

Or you could assign it to a variable for use later like this:

result = add2()

In this case, the 4 is returned to where the add2() is and it is assigned to the variable result.

Hope this helps! :sparkles:

behar
behar
10,800 Points

Yes, im with you on that, i dont think i explained it well enough. My problem is i have the following code:

def HwoBegins():
    first_or_second = 3
    while first_or_second != 1 and first_or_second != 2:
        try:
            first_or_second = int(input("Would you like to play first or second? 1/2 "))
            return first_or_second
        except ValueError:
            print("You can only input 1 or 2!")
            HwoBegins()
        if first_or_second != 1 and first_or_second != 2:
            print("You can only input 1 or 2!")

Now outside of this function i want to make an if statement that contains the first_or_second variable. But python dosent see the variable outside the function. So how would i go about getting that variable outside of that function and use it in a loop?

My idea here was to try to use the return first_or_second and then somehow use whatever was returned by the function.

Remember that i still need to be able to just run the function normally.

Jennifer Nordell
seal-mask
.a{fill-rule:evenodd;}techdegree
Jennifer Nordell
Treehouse Teacher
Jennifer Nordell
.a{fill-rule:evenodd;}techdegree
Jennifer Nordell
Treehouse Teacher

The answer is to return the value of first_or_second. I think this is what you're shooting for:

def HwoBegins():
    first_or_second = 3
    while first_or_second != 1 and first_or_second != 2:
        try:
            first_or_second = int(input("Would you like to play first or second? 1/2 "))
            return first_or_second
        except ValueError:
            print("You can only input 1 or 2!")
            HwoBegins()
        if first_or_second != 1 and first_or_second != 2:
            print("You can only input 1 or 2!")
    return first_or_second  #send out whatever the value of first_or_second is

if(HwoBegins() == 1):   # run the function and get the value returned then compare it to 1
  print("The user picked 1")
else:
  print("The user picked 2")

It's important to understand that the value returned is going to be substituted in place where the call to the function is: HwoBegins() runs the function. A value is returned to that spot. It is then compared to 1.

Hope this helps! :sparkles:

behar
behar
10,800 Points

Yea i dont know why that confused me so much! But got it now, ty so much again!