REF: define inplace ops non-dynamically (pandas-dev#37065)

Author: jbrockmendel

pandas/core/arraylike.py

@@ -6,8 +6,6 @@
 """
 import operator
 
-from pandas.errors import AbstractMethodError
-
 from pandas.core.ops import roperator
 from pandas.core.ops.common import unpack_zerodim_and_defer
 
@@ -17,7 +15,7 @@ class OpsMixin:
     # Comparisons
 
     def _cmp_method(self, other, op):
-        raise AbstractMethodError(self)
+        return NotImplemented
 
     @unpack_zerodim_and_defer("__eq__")
     def __eq__(self, other):
@@ -47,7 +45,7 @@ def __ge__(self, other):
     # Logical Methods
 
     def _logical_method(self, other, op):
-        raise AbstractMethodError(self)
+        return NotImplemented
 
     @unpack_zerodim_and_defer("__and__")
     def __and__(self, other):

pandas/core/frame.py

@@ -9366,7 +9366,6 @@ def _AXIS_NAMES(self) -> Dict[int, str]:
 DataFrame._add_numeric_operations()
 
 ops.add_flex_arithmetic_methods(DataFrame)
-ops.add_special_arithmetic_methods(DataFrame)
 
 
 def _from_nested_dict(data) -> collections.defaultdict:

pandas/core/generic.py

@@ -9799,6 +9799,7 @@ def _tz_localize(ax, tz, ambiguous, nonexistent):
 
     # ----------------------------------------------------------------------
     # Numeric Methods
+
     def abs(self: FrameOrSeries) -> FrameOrSeries:
         """
         Return a Series/DataFrame with absolute numeric value of each element.
@@ -11088,6 +11089,55 @@ def ewm(
             times=times,
         )
 
+    # ----------------------------------------------------------------------
+    # Arithmetic Methods
+
+    def _inplace_method(self, other, op):
+        """
+        Wrap arithmetic method to operate inplace.
+        """
+        result = op(self, other)
+
+        # Delete cacher
+        self._reset_cacher()
+
+        # this makes sure that we are aligned like the input
+        # we are updating inplace so we want to ignore is_copy
+        self._update_inplace(
+            result.reindex_like(self, copy=False), verify_is_copy=False
+        )
+        return self
+
+    def __iadd__(self, other):
+        return self._inplace_method(other, type(self).__add__)
+
+    def __isub__(self, other):
+        return self._inplace_method(other, type(self).__sub__)
+
+    def __imul__(self, other):
+        return self._inplace_method(other, type(self).__mul__)
+
+    def __itruediv__(self, other):
+        return self._inplace_method(other, type(self).__truediv__)
+
+    def __ifloordiv__(self, other):
+        return self._inplace_method(other, type(self).__floordiv__)
+
+    def __imod__(self, other):
+        return self._inplace_method(other, type(self).__mod__)
+
+    def __ipow__(self, other):
+        return self._inplace_method(other, type(self).__pow__)
+
+    def __iand__(self, other):
+        return self._inplace_method(other, type(self).__and__)
+
+    def __ior__(self, other):
+        return self._inplace_method(other, type(self).__or__)
+
+    def __ixor__(self, other):
+        return self._inplace_method(other, type(self).__xor__)
+
     # ----------------------------------------------------------------------
     # Misc methods
 

pandas/core/ops/__init__.py

@@ -33,10 +33,7 @@
 )
 from pandas.core.ops.invalid import invalid_comparison  # noqa:F401
 from pandas.core.ops.mask_ops import kleene_and, kleene_or, kleene_xor  # noqa: F401
-from pandas.core.ops.methods import (  # noqa:F401
-    add_flex_arithmetic_methods,
-    add_special_arithmetic_methods,
-)
+from pandas.core.ops.methods import add_flex_arithmetic_methods  # noqa:F401
 from pandas.core.ops.roperator import (  # noqa:F401
     radd,
     rand_,

pandas/core/ops/methods.py

@@ -49,62 +49,6 @@ def _get_method_wrappers(cls):
     return arith_flex, comp_flex
 
 
-def add_special_arithmetic_methods(cls):
-    """
-    Adds the full suite of special arithmetic methods (``__add__``,
-    ``__sub__``, etc.) to the class.
-
-    Parameters
-    ----------
-    cls : class
-        special methods will be defined and pinned to this class
-    """
-    new_methods = {}
-
-    def _wrap_inplace_method(method):
-        """
-        return an inplace wrapper for this method
-        """
-
-        def f(self, other):
-            result = method(self, other)
-            # Delete cacher
-            self._reset_cacher()
-            # this makes sure that we are aligned like the input
-            # we are updating inplace so we want to ignore is_copy
-            self._update_inplace(
-                result.reindex_like(self, copy=False), verify_is_copy=False
-            )
-
-            return self
-
-        name = method.__name__.strip("__")
-        f.__name__ = f"__i{name}__"
-        return f
-
-    # wrap methods that we get from OpsMixin
-    new_methods.update(
-        dict(
-            __iadd__=_wrap_inplace_method(cls.__add__),
-            __isub__=_wrap_inplace_method(cls.__sub__),
-            __imul__=_wrap_inplace_method(cls.__mul__),
-            __itruediv__=_wrap_inplace_method(cls.__truediv__),
-            __ifloordiv__=_wrap_inplace_method(cls.__floordiv__),
-            __imod__=_wrap_inplace_method(cls.__mod__),
-            __ipow__=_wrap_inplace_method(cls.__pow__),
-        )
-    )
-    new_methods.update(
-        dict(
-            __iand__=_wrap_inplace_method(cls.__and__),
-            __ior__=_wrap_inplace_method(cls.__or__),
-            __ixor__=_wrap_inplace_method(cls.__xor__),
-        )
-    )
-
-    _add_methods(cls, new_methods=new_methods)
-
-
 def add_flex_arithmetic_methods(cls):
     """
     Adds the full suite of flex arithmetic methods (``pow``, ``mul``, ``add``)

pandas/core/series.py

@@ -5005,17 +5005,8 @@ def _arith_method(self, other, op):
 
         return self._construct_result(result, name=res_name)
 
-    def __div__(self, other):
-        # Alias for backward compat
-        return self.__truediv__(other)
-
-    def __rdiv__(self, other):
-        # Alias for backward compat
-        return self.__rtruediv__(other)
-
 
 Series._add_numeric_operations()
 
 # Add arithmetic!
 ops.add_flex_arithmetic_methods(Series)
-ops.add_special_arithmetic_methods(Series)