运算符重载

__add__ 和 _radd_

class Node:
  def __init__(self, num):
    self.n = num
 	
  def __add__(self, other):
    if isinstance(other, Node):
      t = self.n + other.n
    else:
      t = self.n + other
    return t
  
  __radd__ = __add__

上面代码通过自定义__add__来实现Node对象的加法操作。

其中__radd__是为了解决4 + Node的情况，首先尝试(4).__add__(Node)，返回NotImplemented之后，会检查是否定义了__radd__，如果定义了就尝试Node.__radd__(4)。

__truediv__ 和__floordiv__

class Node:
 def __init__(self, num):
   self.n = num
	
 def __truediv__(self, other): # for /
   if isinstance(other, Node):
     t = self.n / other.n
   else:
     t = self.n / other
   return t

 def __floordiv__(self, other): # for //
   if isinstance(other, Node):
     t = self.n // other.n
   else:
     t = self.n // other
   return t