Method _flex_method

pandas/core/series.py:6856–6883

(self, other, op, *, level=None, fill_value=None, axis: Axis = 0)

        return out

    def _flex_method(self, other, op, *, level=None, fill_value=None, axis: Axis = 0):
        if axis is not None:
            self._get_axis_number(axis)

        res_name = ops.get_op_result_name(self, other)

        if isinstance(other, Series):
            return self._binop(other, op, level=level, fill_value=fill_value)
        elif isinstance(other, (np.ndarray, list, tuple, ExtensionArray)):
            if len(other) != len(self):
                raise ValueError("Lengths must be equal")
            other = self._constructor(other, self.index, copy=False)
            result = self._binop(other, op, level=level, fill_value=fill_value)
            result._name = res_name
            return result
        elif isinstance(other, ABCDataFrame):
            # GH#46179
            raise TypeError(
                f"Series.{op.__name__.strip('_')} does not support a DataFrame "
                f"`other`. Use df.{op.__name__.strip('_')}(ser) instead."
            )
        else:
            if fill_value is not None:
                if isna(other):
                    return op(self, fill_value)
                self = self.fillna(fill_value)

            return op(self, other)

    def eq(
        self,