是。例如，有
__radd__。另外，没有用于
__le__()，
__ge__()等的对象，但是正如乔尔·科内特（Joel
Cornett）正确地观察到的那样，如果仅定义
__lt__，则
a > b调用的
__lt__功能
b，这提供了一种解决方法。
>>> class My_Num(object):... def __init__(self, val):... self.val = val... def __radd__(self, other_num):... if isinstance(other_num, My_Num):... return self.val + other_num.val... else:... return self.val + other_num... >>> n1 = My_Num(1)>>> n2 = 3>>> >>> print n2 + n14>>> print n1 + n2Traceback (most recent call last): File "<stdin>", line 1, in <module>TypeError: unsupported operand type(s) for +: 'My_Num' and 'int'
请注意，至少在某些情况下，这样做是合理的：
>>> class My_Num(object):... def __init__(self, val):... self.val = val... def __add__(self, other_num):... if isinstance(other_num, My_Num):... return self.val + other_num.val... else:... return self.val + other_num... __radd__ = __add__
