add gh number

Author: topper-123

doc/source/whatsnew/v2.1.0.rst

@@ -34,7 +34,7 @@ Other enhancements
 - Improve error message when setting :class:`DataFrame` with wrong number of columns through :meth:`DataFrame.isetitem` (:issue:`51701`)
 - Let :meth:`DataFrame.to_feather` accept a non-default :class:`Index` and non-string column names (:issue:`51787`)
 - :class:`api.extensions.ExtensionArray` now has a :meth:`~api.extensions.ExtensionArray.map` method (:issue:`51809`)
-- :meth:`DataFrame.applymap` now uses the :meth:`~api.extensions.ExtensionArray.map` method for of the underlying arrays for :class:`api.extensions.ExtensionArray` instances (:issue:`xxxxx`)
+- :meth:`DataFrame.applymap` now uses the :meth:`~api.extensions.ExtensionArray.map` method for of the underlying arrays for :class:`api.extensions.ExtensionArray` instances (:issue:`52219`)
 - Improve error message when having incompatible columns using :meth:`DataFrame.merge` (:issue:`51861`)
 - Improved error message when creating a DataFrame with empty data (0 rows), no index and an incorrect number of columns. (:issue:`52084`)
 - :meth:`arrays.SparseArray.map` now supports ``na_action`` (:issue:`52096`).

pandas/tests/apply/test_frame_apply.py

@@ -548,7 +548,7 @@ def test_applymap_float_object_conversion(val):
 
 @pytest.mark.parametrize("na_action", ["ignore", None])
 def test_applymap_keeps_dtype(na_action):
-    # GHxxxxx
+    # GH52219
     arr = pd.Series(["a", np.nan, "b"])
     sparse_arr = arr.astype(pd.SparseDtype(object))
     df = pd.DataFrame(data={"a": arr, "b": sparse_arr})