Why do Def programs use return instead of print?

Question

edit: Thank you for the answers! I understand after reading them and playing with it a while.

Answer 1

it use to send data to a new variable where you need that, and suppose you want to use some function that use to get some unique string from a file, and than want to store that string in MySQL.

If you don't use return value, than you have to write it again and again. Writing function for a particular job increase your programing performance.

Answer 2

Sometimes you need to use the answer of a def for something instead of printing. It is much more flexible. A very common way is to set it to a variable in instead of printing.

Answer 3

Err. Imagine having to type every single result for every single calculation, and compare it with the flexibility of functions. Not even close to being comfortable.

Answer 4

use return when you need to asign the result of the function to a variable

def max(a,b):
if a>b:
return a
return b

nMax=max(2,3)

print(nMax) #prints 3