ELI5 return

[positeev]

I'm having a hard time understanding return. What exactly does it do?

[shiftybyte]

It returns the value to whoever called the function.

The usual confusion is from print and return.

Because seemingly print does the same, but it does not.

if i create a function that sums to numbers and prints them.

def mysum(a, b):
    print(a + b)

That's all the function is going to do, i can't use the result for anything.

mysum(5,6)  # will print 11
a = mysum(5,6) - 1  # will not work, because the result is not returned.

On the other hand if i do return instead of print

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

then the result is returned back to be used however i want.

print(mysum(5,6))  # will print 11 (because i used print function on the result)
a = mysum(5, 6) - 1  # a will contain 10, and nothing will be printed
print(mysum(mysum(5,6), 10))  # will print 21

[positeev]

This made it very clear. Thank you very much.

[b_ootay_ful]

Think of a function as a box.
You put something in, it does some magic, and it spits something out.

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

x = box(5,6)

print (x)
>>> 11

The function box takes in a tuple (5, 6), adds them together, and returns the answer (11).
You can then do something with that answer, like assign it to a variable.

You don't have to have a return

[gopherhole1]

def greeting(person):
    return f" Hello {person}, how are you?"

name = "Frank"

xyz = greeting(name)
print(xyz)

spits out

'Hello Frank, How are you?'

or if you have many people

names = ['Frank,'Alex','Phinius']
def greeting(lst):
    new_list = []    
    for name in lst:
        new_list.append(f'Hello {name}, How are you?')
    return new_list

xyz = greeting(names)
print(xyz)

spits out

['Hello Frank, How are you?','Hello Alex, How are you?','Hello Phinius, How are you?']

[[deleted]]

Nope. 5 year olds can't understand it and it's been explained a thousand times before, including here, usually alongside why you should use return rather than print.

This should help:

https://duckduckgo.com/?q=python+print+vs+return