44414 data frame attributes not propagating with astype (#44680)

Author: skwirskj

doc/source/whatsnew/v1.4.0.rst

@@ -652,7 +652,7 @@ Conversion
 - Bug in :class:`IntegerDtype` not allowing coercion from string dtype (:issue:`25472`)
 - Bug in :func:`to_datetime` with ``arg:xr.DataArray`` and ``unit="ns"`` specified raises TypeError (:issue:`44053`)
 - Bug in :meth:`DataFrame.convert_dtypes` not returning the correct type when a subclass does not overload :meth:`_constructor_sliced` (:issue:`43201`)
--
+- Bug in :meth:`DataFrame.astype` not propagating ``attrs`` from the original :class:`DataFrame` (:issue:`44414`)
 
 Strings
 ^^^^^^^

pandas/core/generic.py

@@ -5888,6 +5888,7 @@ def astype(
         # GH 19920: retain column metadata after concat
         result = concat(results, axis=1, copy=False)
         result.columns = self.columns
+        result = result.__finalize__(self, method="astype")
         # https://github.com/python/mypy/issues/8354
         return cast(NDFrameT, result)
 

pandas/tests/frame/methods/test_astype.py

@@ -714,6 +714,16 @@ def test_astype_noncontiguous(self, index_slice):
         expected = df.iloc[index_slice]
         tm.assert_frame_equal(result, expected, check_dtype=False)
 
+    def test_astype_retain_attrs(self, any_numpy_dtype):
+        # GH#44414
+        df = DataFrame({"a": [0, 1, 2], "b": [3, 4, 5]})
+        df.attrs["Location"] = "Michigan"
+
+        result = df.astype({"a": any_numpy_dtype}).attrs
+        expected = df.attrs
+
+        tm.assert_dict_equal(expected, result)
+
 
 class TestAstypeCategorical:
     def test_astype_from_categorical3(self):

pandas/tests/series/methods/test_astype.py

@@ -396,6 +396,16 @@ def test_astype_ea_to_datetimetzdtype(self, dtype):
 
         tm.assert_series_equal(result, expected)
 
+    def test_astype_retain_Attrs(self, any_numpy_dtype):
+        # GH#44414
+        ser = Series([0, 1, 2, 3])
+        ser.attrs["Location"] = "Michigan"
+
+        result = ser.astype(any_numpy_dtype).attrs
+        expected = ser.attrs
+
+        tm.assert_dict_equal(expected, result)
+
 
 class TestAstypeString:
     @pytest.mark.parametrize(