BUG/DEPR: logical operation with bool and string (#61995)

Author: jbrockmendel

doc/source/whatsnew/v2.3.2.rst

@@ -25,7 +25,7 @@ Bug fixes
 - Fix :meth:`~DataFrame.to_json` with ``orient="table"`` to correctly use the
   "string" type in the JSON Table Schema for :class:`StringDtype` columns
   (:issue:`61889`)
-
+- Boolean operations (``|``, ``&``, ``^``) with bool-dtype objects on the left and :class:`StringDtype` objects on the right now cast the string to bool, with a deprecation warning (:issue:`60234`)
 
 .. ---------------------------------------------------------------------------
 .. _whatsnew_232.contributors:

pandas/core/arrays/arrow/array.py

@@ -12,6 +12,7 @@
     overload,
 )
 import unicodedata
+import warnings
 
 import numpy as np
 
@@ -27,6 +28,7 @@
     pa_version_under13p0,
 )
 from pandas.util._decorators import doc
+from pandas.util._exceptions import find_stack_level
 
 from pandas.core.dtypes.cast import (
     can_hold_element,
@@ -852,6 +854,25 @@ def _logical_method(self, other, op) -> Self:
         # integer types. Otherwise these are boolean ops.
         if pa.types.is_integer(self._pa_array.type):
             return self._evaluate_op_method(other, op, ARROW_BIT_WISE_FUNCS)
+        elif (
+            (
+                pa.types.is_string(self._pa_array.type)
+                or pa.types.is_large_string(self._pa_array.type)
+            )
+            and op in (roperator.ror_, roperator.rand_, roperator.rxor)
+            and isinstance(other, np.ndarray)
+            and other.dtype == bool
+        ):
+            # GH#60234 backward compatibility for the move to StringDtype in 3.0
+            op_name = op.__name__[1:].strip("_")
+            warnings.warn(
+                f"'{op_name}' operations between boolean dtype and {self.dtype} are "
+                "deprecated and will raise in a future version. Explicitly "
+                "cast the strings to a boolean dtype before operating instead.",
+                FutureWarning,
+                stacklevel=find_stack_level(),
+            )
+            return op(other, self.astype(bool))
         else:
             return self._evaluate_op_method(other, op, ARROW_LOGICAL_FUNCS)
 

pandas/core/arrays/string_.py

@@ -52,6 +52,7 @@
     missing,
     nanops,
     ops,
+    roperator,
 )
 from pandas.core.algorithms import isin
 from pandas.core.array_algos import masked_reductions
@@ -390,6 +391,26 @@ class BaseStringArray(ExtensionArray):
 
     dtype: StringDtype
 
+    # TODO(4.0): Once the deprecation here is enforced, this method can be
+    #  removed and we use the parent class method instead.
+    def _logical_method(self, other, op):
+        if (
+            op in (roperator.ror_, roperator.rand_, roperator.rxor)
+            and isinstance(other, np.ndarray)
+            and other.dtype == bool
+        ):
+            # GH#60234 backward compatibility for the move to StringDtype in 3.0
+            op_name = op.__name__[1:].strip("_")
+            warnings.warn(
+                f"'{op_name}' operations between boolean dtype and {self.dtype} are "
+                "deprecated and will raise in a future version. Explicitly "
+                "cast the strings to a boolean dtype before operating instead.",
+                FutureWarning,
+                stacklevel=find_stack_level(),
+            )
+            return op(other, self.astype(bool))
+        return NotImplemented
+
     @doc(ExtensionArray.tolist)
     def tolist(self) -> list:
         if self.ndim > 1:

pandas/tests/strings/test_strings.py

@@ -787,3 +787,27 @@ def test_decode_with_dtype_none():
         result = ser.str.decode("utf-8", dtype=None)
         expected = Series(["a", "b", "c"], dtype="str")
         tm.assert_series_equal(result, expected)
+
+
+def test_reversed_logical_ops(any_string_dtype):
+    # GH#60234
+    dtype = any_string_dtype
+    warn = None if dtype == object else FutureWarning
+    left = Series([True, False, False, True])
+    right = Series(["", "", "b", "c"], dtype=dtype)
+
+    msg = "operations between boolean dtype and"
+    with tm.assert_produces_warning(warn, match=msg):
+        result = left | right
+    expected = left | right.astype(bool)
+    tm.assert_series_equal(result, expected)
+
+    with tm.assert_produces_warning(warn, match=msg):
+        result = left & right
+    expected = left & right.astype(bool)
+    tm.assert_series_equal(result, expected)
+
+    with tm.assert_produces_warning(warn, match=msg):
+        result = left ^ right
+    expected = left ^ right.astype(bool)
+    tm.assert_series_equal(result, expected)