What Is a Return Value in Python?

A return value is the result a function sends back after it finishes running.

This is an important Python idea because functions often do work and then give the answer back to the code that called them. A beginner mistake is thinking that print() and return do the same thing. They do not.

Use return when a function should give a result back to your program:

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

result = add(2, 3)
print(result)

Output:

return gives the result back to the caller. Then your code can store it, print it, or use it somewhere else.

What this term means #

A return value is the result a function sends back after it runs.
The return value is created with the return keyword.
The calling code can save that value in a variable, print it, or use it in another expression.

If you are new to functions, see what a function is in Python.

Why return values matter #

Return values matter because they make functions useful.

They let functions produce results.
They make code reusable because the result can be used in different places.
They help separate calculation from display.

For example, a function can calculate a total and return it. Then another part of your program can decide what to do with that total.

Basic example #

Here is a simple function that adds two numbers and returns the answer:

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

result = add(2, 3)
print(result)

Output:

2 and 3 map to parameters a and b; return a + b sends 5 back to the caller.

What happens here:

def add(a, b): creates a function with two inputs.
return a + b sends the sum back.
result = add(2, 3) stores the returned value in a variable.
print(result) shows that value on the screen.

If you need a refresher on function inputs, see what an argument is in Python and what a parameter is in Python.

Return vs print #

This is one of the most common beginner confusions.

print() shows text or values on the screen.
return sends a value back from a function.
A function can return a value without printing anything.
Visible output is not the same as a returned result.

Example using `print()` #

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

result = add(2, 3)
print(result)

Output:

5
None

Why does None appear?

The function prints 5
But it does not return anything
So Python returns None by default
That None gets stored in result

Example using `return` #

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

result = add(2, 3)
print(result)

Output:

If you want to understand print() better, see Python print() function explained.

What happens if there is no return #

If a function does not use return, Python returns None.

def greet():
    print("Hello")

print(greet())

Output:

Hello
None

This surprises many beginners. The function printed "Hello", but it did not send back a useful value.

That is why functions that only print are different from functions that return data.

This also explains some NoneType errors. If your code expects a real value but gets None, you may see errors like AttributeError: ‘NoneType’ object has no attribute … or TypeError: ‘NoneType’ object is not iterable.

Using a return value #

Once a function returns a value, you can use it in different ways.

Save it in a variable #

def get_name():
    return "Maya"

name = get_name()
print(name)

Output:

Maya

Use it in math or string operations #

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

total = add(4, 6)
print(total * 2)

Output:

Pass it into another function #

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

def show_number(number):
    print("The number is:", number)

show_number(add(2, 3))

Output:

The number is: 5

If you want more practice with this idea, see return values in Python functions and Python functions explained.

Common beginner mistakes #

Here are some common problems with return values.

Using `print()` when `return` is needed #

Wrong:

def square(x):
    print(x * x)

result = square(4)
print(result)

Output:

16
None

Better:

def square(x):
    return x * x

result = square(4)
print(result)

Forgetting to capture the returned value #

A function can return a value, but if you do not store or use it, that result may be lost.

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

add(2, 3)  # returned value is ignored

Better:

result = add(2, 3)
print(result)

Writing code after `return` and expecting it to run #

When Python reaches return, the function ends immediately.

def example():
    return 10
    print("This will not run")

The print() line never runs.

Expecting every function to return a useful value #

Some functions return useful data, but some do not. If a function has no return, it gives back None.

Common causes of confusion #

Confusing printed output with returned output
Forgetting that functions without return give back None
Trying to use the result of a function that only prints
Placing important code after a return statement

Helpful checks #

If you are not sure what a function returns, these quick checks can help:

print(add(2, 3))

result = add(2, 3)
print(result)

print(type(result))

You can also inspect built-in functions:

help(print)

help(len)

FAQ #