Adding Variables Inside Functions for Python

 

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  • Using global variables in a function other than the one that created them 18 answers

    • It's because of a thing called scope. You can read up about it, but essentially it means that inside a function, you may not have access to things defined on the outside.

    To make the function aware of these variables, you need to pass them in. Try this: 

    a = 2
b = 3

def add(x, y) :
    x = x + y
    print(str(x))

add(a, b)

    It's worth noting that these values are being passed into the function, but are actually not modified themselves. I won't go into the complexities surrounding the way variables are passed to functions, but suffice it to say that after you call add(a, b) here, the values of a and b will still be 2 and 3, respectively.

    I guess you are just learning about how to do this stuff, and you really don't want to go making everything global or you're going to get in a big mess.

    Here, a and b are passed into the function. Inside the function, a and b are local variables and are distinct from the ones you declared outside the function 

    a = 2
b = 3

def add(a, b) :
    a = a + b
    print(str(a))
    return a

a = add(a, b)

    The return a is so the function returns that local a so you can do something with it

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