1 class Teacher: 2 def __init__(self,name,bitrh,course): 3 self.name=name 4 self.birth=bitrh 5 self.course=course 6 7 class Course: 8 def __init__(self,name,price,period): 9 self.name=name 10 self.price=price 11 self.period=period 12 13 class Date: 14 def __init__(self,year,mon,day): 15 self.year=year 16 self.mon=mon 17 self.day=day 18 19 t=Teacher('egon',Date(1999,1,25),Course('python',11000,'4mons')) 20 print(t.birth.year)