13409.Deprecation

Using non-:class:~collections.abc.Collection iterables (such as generators, iterators, or custom iterable objects) for the argvalues parameter in :ref:@pytest.mark.parametrize <pytest.mark.parametrize ref> and :meth:metafunc.parametrize <pytest.Metafunc.parametrize> is now deprecated.

These iterables get exhausted after the first iteration, leading to tests getting unexpectedly skipped in cases such as running :func:pytest.main() multiple times, using class-level parametrize decorators, or collecting tests multiple times.

See :ref:parametrize-iterators for details and suggestions.