fix categoricals

Author: topper-123

doc/source/whatsnew/v1.2.0.rst

@@ -484,7 +484,6 @@ Deprecations
 - Deprecated :meth:`Index.asi8` for :class:`Index` subclasses other than :class:`.DatetimeIndex`, :class:`.TimedeltaIndex`, and :class:`PeriodIndex` (:issue:`37877`)
 - The ``inplace`` parameter of :meth:`Categorical.remove_unused_categories` is deprecated and will be removed in a future version (:issue:`37643`)
 - The ``null_counts`` parameter of :meth:`DataFrame.info` is deprecated and replaced by ``show_counts``. It will be removed in a future version (:issue:`37999`)
-- Deprecated membership checks for nan-likes in :class:`Categorical`. In the future the membership check will only return True if the nan-like is ``nan`` or of the same dtype as the underlying categories (:issue:`37867`)
 
 .. ---------------------------------------------------------------------------
 

pandas/core/arrays/categorical.py

@@ -1749,13 +1749,6 @@ def __contains__(self, key) -> bool:
 
         # if key is a NaN, check if any NaN is in self.
         if is_valid_nat_for_dtype(key, self.categories.dtype):
-            if key is not self.dtype.na_value and not isinstance(key, self.dtype.type):
-                warn(
-                    f"Membership check with {key} will return False in the future. "
-                    f"Consider using {self.dtype.na_value} instead",
-                    FutureWarning,
-                    stacklevel=2,
-                )
             return self.isna().any()
 
         return contains(self, key, container=self._codes)

pandas/tests/extension/test_categorical.py

@@ -109,9 +109,8 @@ def test_contains(self, data, data_missing):
             if na_value_type is na_value:
                 continue
 
-            with tm.assert_produces_warning(FutureWarning, check_stacklevel=False):
-                assert na_value_type not in data
-                assert na_value_type in data_missing
+            assert na_value_type not in data
+            assert na_value_type in data_missing
 
 
 class TestConstructors(base.BaseConstructorsTests):