PR feedback: issue reference and whatsnew

Author: AndrewEckart

doc/source/whatsnew/v1.4.0.rst

@@ -211,7 +211,7 @@ Other enhancements
 - :meth:`.GroupBy.mean` now supports `Numba <http://numba.pydata.org/>`_ execution with the ``engine`` keyword (:issue:`43731`)
 - :meth:`Timestamp.isoformat`, now handles the ``timespec`` argument from the base :class:``datetime`` class (:issue:`26131`)
 - :meth:`NaT.to_numpy` ``dtype`` argument is now respected, so ``np.timedelta64`` can be returned (:issue:`44460`)
--
+- :meth:`Categorical.value_counts` now supports the argument ``observed`` (:issue:`43498`)
 
 .. ---------------------------------------------------------------------------
 

pandas/tests/extension/test_categorical.py

@@ -164,6 +164,8 @@ def test_value_counts(self, all_data, dropna):
         return super().test_value_counts(all_data, dropna)
 
     def test_value_counts_observed(self, data):
+        # GH 43498
+        # When observed=True is passed, unobserved categories should be omitted
         data = data.add_categories(["#", "?"])  # Add some unobserved categories
         series = pd.Series(data, dtype=data.categories.dtype)
         result = data.value_counts(observed=True).sort_index()