update

Author: topper-123

doc/source/whatsnew/v2.1.0.rst

@@ -289,6 +289,7 @@ Performance improvements
 - Performance improvement in :func:`concat` when ``axis=1`` and objects have different indexes (:issue:`52541`)
 - Performance improvement in :meth:`.DataFrameGroupBy.groups` (:issue:`53088`)
 - Performance improvement in :meth:`DataFrame.loc` when selecting rows and columns (:issue:`53014`)
+- Performance improvement in :meth:`DataFrame.transpose` when transposing a DataFrame with a single masked dtype, e.g. :class:`Int64` (:issue:`52836`)
 - Performance improvement in :meth:`Series.corr` and :meth:`Series.cov` for extension dtypes (:issue:`52502`)
 - Performance improvement in :meth:`Series.to_numpy` when dtype is a numpy float dtype and ``na_value`` is ``np.nan`` (:issue:`52430`)
 - Performance improvement in :meth:`~arrays.ArrowExtensionArray.to_numpy` (:issue:`52525`)

pandas/core/frame.py

@@ -3588,6 +3588,7 @@ def transpose(self, *args, copy: bool = False) -> DataFrame:
             )
             if using_copy_on_write() and len(self) > 0:
                 result._mgr.add_references(self._mgr)  # type: ignore[arg-type]
+
         elif (
             self._is_homogeneous_type
             and dtypes