Return values from functions

Completed

Most useful functions don't just do something—they produce a result the caller can use. That result is passed back with the return statement.

Returning a value

Use return to send a value out of a function. Once return runs, the function ends immediately.

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

result = add(3, 4)
print(result)   # Output: 7

You can use the returned value directly in an expression:

print(add(10, 5) * 2)   # Output: 30

In this example, the add() function returns the sum of its two parameters, and that value is used in the multiplication expression before it's printed.

Return vs. print

Notice the difference between print() and return:

• print() displays a value to the console.
• return gives a value back to the caller so it can be stored, used, or passed to another function.

def add(a, b):
    print(a + b)   # Shows the result but returns None

x = add(3, 4)
print(x)           # Output: None

If you want to use the result of a function, you must use return instead of print().

Returning multiple values

A function can return more than one value by separating them with commas. Python packages them into a tuple you can unpack on the receiving end:

#coordinates example
def get_coordinates():
    return 10.0, 20.0

x, y = get_coordinates()
print(f"x: {x}, y: {y}")   # Output: x: 10.0, y: 20.0

Functions with no return value

A function that doesn't include a return statement still returns something—the special value None.

def greet(name):
    print(f"Hello, {name}!")

result = greet("Alex")
print(result)   # Output: None

That's fine when the function's purpose is to do something (like print or write to a file) rather than produce a value.