REGR: fix Series construction from dict for subclasses

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

@@ -561,12 +561,7 @@ 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)