class Hoge:
	def __init__(self,x,y):
		self.__x = x
		self.__y = y
 
	@classmethod
	def sum(self,x=None,y=None):
		if x==None and y==None:
			print(self.x, self.y)
			try:
				print(self.__x)
			except:
				self.error()
		else:
			print(x+y)
 
	@classmethod
	def error(self):
		print('error')
		print(self.x)
 
	@property
	def x(self):
		return self.__x
 
	@property
	def y(self):
		return self.__y
 
h = Hoge(10,20)
h.sum()
h.sum(h.x, h.y)
 
Hoge.sum(33,44)

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