CLN: Remove __nonzero__ in favor of __bool__

pandas/core/generic.py

@@ -1491,14 +1491,12 @@ def __invert__(self) -> Self:
         return res.__finalize__(self, method="__invert__")
 
     @final
-    def __nonzero__(self) -> NoReturn:
+    def __bool__(self) -> NoReturn:
         raise ValueError(
             f"The truth value of a {type(self).__name__} is ambiguous. "
             "Use a.empty, a.bool(), a.item(), a.any() or a.all()."
         )
 
-    __bool__ = __nonzero__
-
     @final
     def abs(self) -> Self:
         """

pandas/core/indexes/base.py

@@ -2907,14 +2907,12 @@ def __iadd__(self, other):
         return self + other
 
     @final
-    def __nonzero__(self) -> NoReturn:
+    def __bool__(self) -> NoReturn:
         raise ValueError(
             f"The truth value of a {type(self).__name__} is ambiguous. "
             "Use a.empty, a.bool(), a.item(), a.any() or a.all()."
         )
 
-    __bool__ = __nonzero__
-
     # --------------------------------------------------------------------
     # Set Operation Methods
 

pandas/core/internals/managers.py

@@ -263,12 +263,9 @@ def make_empty(self, axes=None) -> Self:
             blocks = []
         return type(self).from_blocks(blocks, axes)
 
-    def __nonzero__(self) -> bool:
+    def __bool__(self) -> bool:
         return True
 
-    # Python3 compat
-    __bool__ = __nonzero__
-
     def set_axis(self, axis: AxisInt, new_labels: Index) -> None:
         # Caller is responsible for ensuring we have an Index object.
         self._validate_set_axis(axis, new_labels)