Python 按右侧对象处理操作（_r*__方法）

当

numpy.array

位于右侧时，

numpy

如何处理操作

>>> [1,2,3]+numpy.array([1,2,3])
array([2, 4, 6])

我认为

list

应该尝试将

array

（使用

list.\uuuu add\uuuu

方法）添加到自身中，然后失败

---

@M4rtini答案的附加示例：

\uuuuuu radd\uuuuuu

在

\uuuuu add\uuuuuu

失败且对象类型不同时调用

\uuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuu

class A():
    def __radd__(self, other):
        return "result"
print(A()+A()) #fail with TypeError

调用这些方法来实现二进制算术运算 （+，-，*，/，%，divmod（），pow（），**，&，^，|）带反射 （交换）操作数仅当左侧 操作数不支持相应的操作和操作数 属于不同的类型。[2]

---

\uuuuu radd\uuuuu

在

\uuuu add\uuuuuuuu>失败时调用get。它的可能副本可能不是直接副本，但那里的答案解释了这一点behavior@M4rtini更新评论请不要为同一类型的两个对象调用
\uuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuu
，Python文档中有没有规定失败时调用
\uuuuuuuuuuuuuuuuuuuuuuuuu，它不是用相同类型的对象调用的？我好几天都没弄明白：）说得很清楚，是我的错
class A(object):
    def __radd__(self, other):
        print ("__radd__ called of A")
        return "result of A"

class B(object):
    def __radd__(self, other):
        print ("__radd__ called of B")
        return "result of B"


print (B()+A())
print (A()+B())

>>__radd__ called of A
>>result of A
>>__radd__ called of B
>>result of B

object.__radd__(self, other)
object.__rsub__(self, other)
object.__rmul__(self, other)
object.__rdiv__(self, other)
object.__rtruediv__(self, other)
object.__rfloordiv__(self, other)
object.__rmod__(self, other)
object.__rdivmod__(self, other)
object.__rpow__(self, other)
object.__rlshift__(self, other)
object.__rrshift__(self, other)
object.__rand__(self, other)
object.__rxor__(self, other)
object.__ror__(self, other)