Backport PR #31187: BUG: IntegerArray.astype(boolean) (#31254)

Author: meeseeksmachine

pandas/core/arrays/integer.py

@@ -19,6 +19,7 @@
     is_list_like,
     is_object_dtype,
     is_scalar,
+    pandas_dtype,
 )
 from pandas.core.dtypes.dtypes import register_extension_dtype
 from pandas.core.dtypes.missing import isna
@@ -440,11 +441,17 @@ def astype(self, dtype, copy=True):
             if incompatible type with an IntegerDtype, equivalent of same_kind
             casting
         """
+        from pandas.core.arrays.boolean import BooleanArray, BooleanDtype
+
+        dtype = pandas_dtype(dtype)
 
         # if we are astyping to an existing IntegerDtype we can fastpath
         if isinstance(dtype, _IntegerDtype):
             result = self._data.astype(dtype.numpy_dtype, copy=False)
             return type(self)(result, mask=self._mask, copy=False)
+        elif isinstance(dtype, BooleanDtype):
+            result = self._data.astype("bool", copy=False)
+            return BooleanArray(result, mask=self._mask, copy=False)
 
         # coerce
         if is_float_dtype(dtype):

pandas/tests/arrays/test_integer.py

@@ -680,6 +680,13 @@ def test_astype_str(self):
         tm.assert_numpy_array_equal(a.astype(str), expected)
         tm.assert_numpy_array_equal(a.astype("str"), expected)
 
+    def test_astype_boolean(self):
+        # https://github.com/pandas-dev/pandas/issues/31102
+        a = pd.array([1, 0, -1, 2, None], dtype="Int64")
+        result = a.astype("boolean")
+        expected = pd.array([True, False, True, True, None], dtype="boolean")
+        tm.assert_extension_array_equal(result, expected)
+
 
 def test_frame_repr(data_missing):