BUG: df constructor not copying ea backed series (#53744)

Co-authored-by: Joris Van den Bossche <[email protected]>

Author: phofl

doc/source/whatsnew/v2.1.0.rst

@@ -516,6 +516,7 @@ Sparse
 
 ExtensionArray
 ^^^^^^^^^^^^^^
+- Bug in :class:`DataFrame` constructor not copying :class:`Series` with extension dtype when given in dict (:issue:`53744`)
 - Bug in :class:`~arrays.ArrowExtensionArray` converting pandas non-nanosecond temporal objects from non-zero values to zero values (:issue:`53171`)
 - Bug in :meth:`Series.quantile` for pyarrow temporal types raising ArrowInvalid (:issue:`52678`)
 - Bug in :meth:`Series.rank` returning wrong order for small values with ``Float64`` dtype (:issue:`52471`)

pandas/core/internals/construction.py

@@ -469,7 +469,11 @@ def dict_to_mgr(
                 x.copy()
                 if isinstance(x, ExtensionArray)
                 else x.copy(deep=True)
-                if isinstance(x, Index)
+                if (
+                    isinstance(x, Index)
+                    or isinstance(x, ABCSeries)
+                    and is_1d_only_ea_dtype(x.dtype)
+                )
                 else x
                 for x in arrays
             ]

pandas/tests/frame/test_constructors.py

@@ -2576,6 +2576,13 @@ def check_views(c_only: bool = False):
             # TODO: we can check b[0] == 0 if we stop consolidating in
             #  setitem_with_indexer (except for datetimelike?)
 
+    def test_construct_from_dict_ea_series(self):
+        # GH#53744 - default of copy=True should also apply for Series with
+        # extension dtype
+        ser = Series([1, 2, 3], dtype="Int64")
+        df = DataFrame({"a": ser})
+        assert not np.shares_memory(ser.values._data, df["a"].values._data)
+
     def test_from_series_with_name_with_columns(self):
         # GH 7893
         result = DataFrame(Series(1, name="foo"), columns=["bar"])