python 运算符 供重载参考
| 二元运算符 | 特殊方法 |
| + | __add__,__radd__ |
| - | __sub__,__rsub__ |
| * | __mul__,__rmul__ |
| / | __div__,__rdiv__,__truediv__,__rtruediv__ |
| // | __floordiv__,__rfloordiv__ |
| % | __mod__,__rmod__ |
| ** | __pow__,__rpow__ |
| << | __lshift__,__rlshift__ |
| >> | __rshift__,__rrshift__ |
| & | __and__,__rand__ |
| ^ | __xor__,__rxor__ |
| | | __or__,__ror__ |
| += | __iaddr__ |
| -= | __isub__ |
| *= | __imul__ |
| /= | __idiv__,__itruediv__ |
| //= | __ifloordiv__ |
| %= | __imod__ |
| **= | __ipow__ |
| <<= | __ilshift__ |
| >>= | __irshift__ |
| &= | __iand__ |
| ^= | __ixor__ |
| |= | __ior__ |
| == | __eq__ |
| !=,<> | __ne__ |
| > | __get__ |
| < | __lt__ |
| >= | __ge__ |
| <= | __le__ |