groupby tests

Author: jreback

pandas/core/internals/blocks.py

@@ -1762,7 +1762,7 @@ def _try_cast_result(self, result, dtype=None):
         try:
 
             result = self._holder._from_sequence(
-                np.asarray(result).ravel(), dtype=dtype)
+                result.ravel(), dtype=dtype)
         except Exception:
             pass
 

pandas/tests/extension/base/groupby.py

@@ -64,6 +64,18 @@ def test_groupby_extension_apply(
         df.groupby("A").apply(groupby_apply_op)
         df.groupby("A").B.apply(groupby_apply_op)
 
+    def test_groupby_apply_identity(self, data_for_grouping):
+        df = pd.DataFrame({"A": [1, 1, 2, 2, 3, 3, 1, 4],
+                           "B": data_for_grouping})
+        result = df.groupby('A').B.apply(lambda x: x.array)
+        expected = pd.Series([df.B.iloc[[0, 1, 6]].array,
+                              df.B.iloc[[2, 3]].array,
+                              df.B.iloc[[4, 5]].array,
+                              df.B.iloc[[7]].array],
+                             index=pd.Index([1, 2, 3, 4], name='A'),
+                             name='B')
+        self.assert_series_equal(result, expected)
+
     def test_in_numeric_groupby(self, data_for_grouping):
         df = pd.DataFrame({"A": [1, 1, 2, 2, 3, 3, 1, 4],
                            "B": data_for_grouping,

pandas/tests/extension/decimal/test_decimal.py

@@ -192,7 +192,11 @@ class TestCasting(BaseDecimal, base.BaseCastingTests):
 
 
 class TestGroupby(BaseDecimal, base.BaseGroupbyTests):
-    pass
+
+    @pytest.mark.xfail(
+        reason="needs to correctly define __eq__ to handle nans, xref #27081.")
+    def test_groupby_apply_identity(self, data_for_grouping):
+        super().test_groupby_apply_idendeity(data_for_grouping)
 
 
 class TestSetitem(BaseDecimal, base.BaseSetitemTests):