Carve-out for array-castable attributes

Author: jbrockmendel

pandas/core/arrays/arrow/array.py

@@ -943,8 +943,10 @@ def _op_method_error_message(self, other, op) -> str:
         )
 
     def _evaluate_op_method(self, other, op, arrow_funcs) -> Self:
-        if is_list_like(other) and not isinstance(
-            other, (np.ndarray, ExtensionArray, list)
+        if (
+            is_list_like(other)
+            and not isinstance(other, (np.ndarray, ExtensionArray, list))
+            and not ops.has_castable_attr(other)
         ):
             warnings.warn(
                 f"Operation with {type(other).__name__} are deprecated. "

pandas/core/arrays/boolean.py

@@ -382,7 +382,9 @@ def _logical_method(self, other, op):
         if isinstance(other, BooleanArray):
             other, mask = other._data, other._mask
         elif is_list_like(other):
-            if not isinstance(other, (list, ExtensionArray, np.ndarray)):
+            if not isinstance(
+                other, (list, ExtensionArray, np.ndarray)
+            ) and not ops.has_castable_attr(other):
                 warnings.warn(
                     f"Operation with {type(other).__name__} are deprecated. "
                     "In a future version these will be treated as scalar-like. "

pandas/core/arrays/datetimelike.py

@@ -970,7 +970,9 @@ def _cmp_method(self, other, op):
             return op(self.ravel(), other.ravel()).reshape(self.shape)
 
         if is_list_like(other):
-            if not isinstance(other, (list, np.ndarray, ExtensionArray)):
+            if not isinstance(
+                other, (list, np.ndarray, ExtensionArray)
+            ) and not ops.has_castable_attr(other):
                 warnings.warn(
                     f"Operation with {type(other).__name__} are deprecated. "
                     "In a future version these will be treated as scalar-like. "

pandas/core/arrays/interval.py

@@ -75,6 +75,7 @@
     notna,
 )
 
+from pandas.core import ops
 from pandas.core.algorithms import (
     isin,
     take,
@@ -845,7 +846,9 @@ def __setitem__(self, key, value) -> None:
     def _cmp_method(self, other, op):
         # ensure pandas array for list-like and eliminate non-interval scalars
         if is_list_like(other):
-            if not isinstance(other, (list, np.ndarray, ExtensionArray)):
+            if not isinstance(
+                other, (list, np.ndarray, ExtensionArray)
+            ) and not ops.has_castable_attr(other):
                 warnings.warn(
                     f"Operation with {type(other).__name__} are deprecated. "
                     "In a future version these will be treated as scalar-like. "

pandas/core/arrays/masked.py

@@ -747,8 +747,10 @@ def _arith_method(self, other, op):
         op_name = op.__name__
         omask = None
 
-        if is_list_like(other) and not isinstance(
-            other, (list, np.ndarray, ExtensionArray)
+        if (
+            is_list_like(other)
+            and not isinstance(other, (list, np.ndarray, ExtensionArray))
+            and not ops.has_castable_attr(other)
         ):
             warnings.warn(
                 f"Operation with {type(other).__name__} are deprecated. "
@@ -863,7 +865,9 @@ def _cmp_method(self, other, op) -> BooleanArray:
             other, mask = other._data, other._mask
 
         elif is_list_like(other):
-            if not isinstance(other, (list, np.ndarray, ExtensionArray)):
+            if not isinstance(
+                other, (list, np.ndarray, ExtensionArray)
+            ) and not ops.has_castable_attr(other):
                 warnings.warn(
                     f"Operation with {type(other).__name__} are deprecated. "
                     "In a future version these will be treated as scalar-like. "

pandas/core/arrays/sparse/array.py

@@ -69,7 +69,10 @@
     notna,
 )
 
-from pandas.core import arraylike
+from pandas.core import (
+    arraylike,
+    ops,
+)
 import pandas.core.algorithms as algos
 from pandas.core.arraylike import OpsMixin
 from pandas.core.arrays import ExtensionArray
@@ -1808,7 +1811,9 @@ def _arith_method(self, other, op):
             return _wrap_result(op_name, result, self.sp_index, fill)
 
         else:
-            if not isinstance(other, (list, np.ndarray, ExtensionArray)):
+            if not isinstance(
+                other, (list, np.ndarray, ExtensionArray)
+            ) and not ops.has_castable_attr(other):
                 warnings.warn(
                     f"Operation with {type(other).__name__} are deprecated. "
                     "In a future version these will be treated as scalar-like. "
@@ -1830,8 +1835,10 @@ def _arith_method(self, other, op):
                 return _sparse_array_op(self, other, op, op_name)
 
     def _cmp_method(self, other, op) -> SparseArray:
-        if is_list_like(other) and not isinstance(
-            other, (list, np.ndarray, ExtensionArray)
+        if (
+            is_list_like(other)
+            and not isinstance(other, (list, np.ndarray, ExtensionArray))
+            and not ops.has_castable_attr(other)
         ):
             warnings.warn(
                 f"Operation with {type(other).__name__} are deprecated. "

pandas/core/arrays/string_.py

@@ -1102,7 +1102,9 @@ def _cmp_method(self, other, op):
         valid = ~mask
 
         if lib.is_list_like(other):
-            if not isinstance(other, (list, ExtensionArray, np.ndarray)):
+            if not isinstance(
+                other, (list, ExtensionArray, np.ndarray)
+            ) and not ops.has_castable_attr(other):
                 warnings.warn(
                     f"Operation with {type(other).__name__} are deprecated. "
                     "In a future version these will be treated as scalar-like. "

pandas/core/frame.py

@@ -8485,7 +8485,9 @@ def to_series(right):
                 )
 
         elif is_list_like(right) and not isinstance(right, (Series, DataFrame)):
-            if not isinstance(right, (np.ndarray, ExtensionArray, Index, list, dict)):
+            if not isinstance(
+                right, (np.ndarray, ExtensionArray, Index, list, dict)
+            ) and not ops.has_castable_attr(right):
                 warnings.warn(
                     f"Operation with {type(right).__name__} are deprecated. "
                     "In a future version these will be treated as scalar-like. "

pandas/core/ops/__init__.py

@@ -17,6 +17,7 @@
 )
 from pandas.core.ops.common import (
     get_op_result_name,
+    has_castable_attr,
     unpack_zerodim_and_defer,
 )
 from pandas.core.ops.docstrings import make_flex_doc
@@ -71,6 +72,7 @@
     "fill_binop",
     "get_array_op",
     "get_op_result_name",
+    "has_castable_attr",
     "invalid_comparison",
     "kleene_and",
     "kleene_or",

pandas/core/ops/common.py

@@ -21,6 +21,11 @@
     from pandas._typing import F
 
 
+def has_castable_attr(obj) -> bool:
+    attrs = ["__array__", "__dlpack__", "__arrow_c_array__", "__arrow_c_stream__"]
+    return any(hasattr(obj, name) for name in attrs)
+
+
 def unpack_zerodim_and_defer(name: str) -> Callable[[F], F]:
     """
     Boilerplate for pandas conventions in arithmetic and comparison methods.