implicit-return (RET503)

Derived from the flake8-return linter.

Fix is always available.

What it does

Checks for missing explicit return statements at the end of functions that can return non-None values.

Why is this bad?

The lack of an explicit return statement at the end of a function that can return non-None values can cause confusion. Python implicitly returns None if no other return value is present. Adding an explicit return None can make the code more readable by clarifying intent.

Example

def foo(bar):
    if not bar:
        return 1

Use instead:

def foo(bar):
    if not bar:
        return 1
    return None