class Time60(object):
   def __init__(self,hr,min):
      self.hr=hr
      self.min=min

   def __add__(self, other):        #__add__ 相当于加：+操作符
      return self.__class__(self.hr+other.hr,self.min+other.min)
      #self.__class__()等价Time60()

   def __str__(self):
      return '%d:%d'%(self.hr,self.min)
   __repr__=__str__

   def __iadd__(self, other):       #__iadd__相当于：+=操作符
      self.hr+=other.hr
      self.min+=other.min
      return self

test1=Time60(1,30)
test2=Time60(12,45)
print(test1,test2)
print(test1+test2)
test1+=test2
print(test1)