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invalid-hash-return-type (PLE0309)

Added in 0.6.0 · Related issues · View source

Derived from the Pylint linter.

What it does

Checks for __hash__ implementations that return non-integer values.

Why is this bad?

The __hash__ method should return an integer. Returning a different type may cause unexpected behavior.

Note: bool is a subclass of int, so it's technically valid for __hash__ to return True or False. However, for consistency with other rules, Ruff will still emit a diagnostic when __hash__ returns a bool.

Example

class Foo:
    def __hash__(self):
        return "2"

Use instead:

class Foo:
    def __hash__(self):
        return 2

References