class class1(): def __init__(self): self.User = User(param1, param2, param3) ..... def next(self): self.next = class2(self.User) class class2(): def __init__(self, user): self.User = user def do_smth(self): self.User.name = 'Oleg' def next(self): self.next = class3(self.User) class class3(): def __init__(self, user): self.User = user def do_smth(self): self.User.surname = 'Olegovich'