Class - error return

[Smith]

Hi,
you can help me ?
I can not understand where is the error in this script.
Use Python3.


In [71]: class Day(object):
     ...:     def __init__(self,visits,contacts):
     ...:         self.visits = visits
     ...:         self.contacts = contacts
     ...:     def __add__(self,other):
     ...:         total_visits = self.visits + other.visits
     ...:         total_contacts = self.contacts + other.contacts
     ...:         return Day(total_visits,total_contacts)
     ...:     def __radd__(self,other):
     ...:         if other == 0:
     ...:             return self
     ...:         else:
     ...:             return self.__add__(other)
     ...:     def __str__(self):
     ...:         return "Visitor: %i, Contacts: %i % 
(self.visits,self.contacts)"
     ...:
     ...:



In [72]: day1 = Day(8,9)

In [73]: day2 = Day(7,7)

In [74]: print(day1)
Visitor: %i, Contacts: %i % (self.visits,self.contacts)

In [75]: print(day2)
Visitor: %i, Contacts: %i % (self.visits,self.contacts)