Python Function Return None Without Return Statement

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The Python return keyword allows you to define the return value of a function (e.g., return X). If you don’t explicitly set a return value or you omit the return statement, Python will implicitly return the following default value: None.

Python Function Return None Without Return Statement

There are three cases of what a function can return:

  • Case 1: The function has a return statement that returns an explicit value.
  • Case 2: The function has a return statement that returns explicitly nothing. It returns None.
  • Case 3: The function does not have a return statement. The function in that case implicitly returns None.

Let’s have an example of all three cases next!

Case 1: The function has a return statement that returns an explicit value.

def f1():
    return 42

print(f1())
# 42

Case 2: The function has a return statement that returns explicitly nothing. It returns None.

def f2():
    return

print(f2())
# None

Case 3: The function does not have a return statement. The function in that case implicitly returns None.

def f3():
    pass

print(f3())
# None

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