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invalid-bool-return-type (PLE0304)

Preview (since v0.3.3) · Related issues · View source

Derived from the Pylint linter.

This rule is unstable and in preview. The --preview flag is required for use.

What it does

Checks for __bool__ implementations that return a type other than bool.

Why is this bad?

The __bool__ method should return a bool object. Returning a different type may cause unexpected behavior.

Example

class Foo:
    def __bool__(self):
        return 2

Use instead:

class Foo:
    def __bool__(self):
        return True

References