Backport PR #52516 on branch 2.0.x (REGR: fix Series construction fro…

…m dict for subclasses) (#52520)

Backport PR #52516: REGR: fix Series construction from dict for subclasses

Co-authored-by: Joris Van den Bossche <jorisvandenbossche@gmail.com>

doc/source/whatsnew/v2.0.1.rst

@@ -13,7 +13,7 @@ including other versions of pandas.
 
 Fixed regressions
 ~~~~~~~~~~~~~~~~~
--
+- Fixed regression for subclassed Series when constructing from a dictionary (:issue:`52445`)
 
 .. ---------------------------------------------------------------------------
 .. _whatsnew_201.bug_fixes:

pandas/core/series.py

@@ -562,12 +562,7 @@ def _init_dict(
             keys, values = (), []
 
         # Input is now list-like, so rely on "standard" construction:
-
-        s = self._constructor(
-            values,
-            index=keys,
-            dtype=dtype,
-        )
+        s = Series(values, index=keys, dtype=dtype)
 
         # Now we just make sure the order is respected, if any
         if data and index is not None:

pandas/tests/series/test_subclass.py

@@ -58,3 +58,21 @@ def test_equals(self):
         s2 = tm.SubclassedSeries([1, 2, 3])
         assert s1.equals(s2)
         assert s2.equals(s1)
+
+
+class SubclassedSeries(pd.Series):
+    @property
+    def _constructor(self):
+        def _new(*args, **kwargs):
+            # some constructor logic that accesses the Series' name
+            if self.name == "test":
+                return pd.Series(*args, **kwargs)
+            return SubclassedSeries(*args, **kwargs)
+
+        return _new
+
+
+def test_constructor_from_dict():
+    # https://github.com/pandas-dev/pandas/issues/52445
+    result = SubclassedSeries({"a": 1, "b": 2, "c": 3})
+    assert isinstance(result, SubclassedSeries)