6.4.5.13.py

#6.4.1.13

print("6.4.1.13\n")

class WeekDayError(Exception):
    pass
	

class Weeker:
    __names =['Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat', 'Sun']
    
    def __init__(self, day):
        try:
            self.__current=Weeker.__names.index(day)
            
        except ValueError:
            raise WeekDayError
       
    def __str__(self):
        return Weeker.__names[self.__current]
        
        

    def add_days(self, n):
        self.__current=(self.__current+n)%7
        
        
        

    def subtract_days(self, n):
        self.__current=(self.__current-n)%7
        
        
        


try:
    weekday = Weeker('Mon')
    print(weekday)
    weekday.add_days(700)
    print(weekday)
    weekday.subtract_days(23)
    print(weekday)
    weekday = Weeker('Monday')
except WeekDayError:
    print("Sorry, I can't serve your request.")