__repr__ method should return a string that could be used as executable code to re-create the object : repr « Class « Python Tutorial

1. Python Tutorial
2. Class
3. repr

class adder: 
    def __init__(self, value=0): 
        self.data = value                     
    def __add__(self, other): 
        self.data += other                    



class addboth(adder): 
    def __str__(self): 
        return '[Value: %s]' % self.data      
    def __repr__(self): 
        return 'addboth(%s)' % self.data      

x = addboth(4) 
print x                                       
str(x), repr(x)