1 class Square:
 2     def __init__(self, wh):  #因为是正方形, 只取一条边的长度
 3         if isinstance(wh,(int,float)):
 4             self.wh = wh
 5         else:
 6             raise TypeError
 7 
 8     def __add__(self, other):
 9         self_area = self.wh * self.wh     #计算self面积
10         other_area = other.wh * other.wh  #计算other面积
11         return self_area + other_area     #相加 x+y
12 
13     def __sub__(self,other):
14         self_area = self.wh * self.wh     #计算self面积
15         other_area = other.wh * other.wh  #计算other面积
16         return self_area - other_area     #相减 x-y
17     
18     def __mul__(self,other):
19         self_area = self.wh * self.wh     #计算self面积
20         other_area = other.wh * other.wh  #计算other面积
21         return self_area * other_area     #相乘 x*y
22     
23     def __mod__(self,other):    
24         self_area = self.wh * self.wh     #计算self面积
25         other_area = other.wh * other.wh  #计算other面积
26         return self_area % other_area     #相除 x%y
27 
28 s1 = Square(3)
29 s2 = Square(4)