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non-pep604-isinstance (UP038)

Removed (since 0.13.0) · Related issues · View source

Derived from the pyupgrade linter.

Warning: This rule has been removed and its documentation is only available for historical reasons.

Fix is always available.

Removed

This rule was removed as using PEP 604 syntax in isinstance and issubclass calls isn't recommended practice, and it incorrectly suggests that other typing syntaxes like PEP 695 would be supported by isinstance and issubclass. Using the PEP 604 syntax is also slightly slower.

What it does

Checks for uses of isinstance and issubclass that take a tuple of types for comparison.

Why is this bad?

Since Python 3.10, isinstance and issubclass can be passed a |-separated union of types, which is consistent with the union operator introduced in PEP 604.

Note that this results in slower code. Ignore this rule if the performance of an isinstance or issubclass check is a concern, e.g., in a hot loop.

Example

isinstance(x, (int, float))

Use instead:

isinstance(x, int | float)

Options

References