no enclosing class or function found - Ruff

What it does

Detects invalid super() calls where implicit arguments like the enclosing class or first method argument are unavailable.

Why is this bad?

When super() is used without arguments, Python tries to find two things: the nearest enclosing class and the first argument of the immediately enclosing function (typically self or cls). If either of these is missing, the call will fail at runtime with a RuntimeError.

Examples

python

# no enclosing class or function found
super()  # error


def func():
    # no enclosing class or first argument exists
    super()  # error


class A:
    # no enclosing function to provide the first argument
    f = super()  # error

    def method(self):
        def nested():
            # first argument does not exist in this nested function
            super()  # error

        # first argument does not exist in this lambda
        lambda: super()  # error

        # argument is not available in generator expression
        (super() for _ in range(10))  # error

        super()  # okay! both enclosing class and first argument are available

References

Python documentation: super()