Derived class

Derivation

• Derived: This process subclasses newly defined attribute called forking and subclasses need to remember when using the derived attributes are always subject to their own

A derivation method

• By name access functions of a particular class: the way has nothing to do with inheritance

class OldboyPeople:
    """由于学生和老师都是人，因此人都有姓名、年龄、性别"""
    school = 'oldboy'

    def __init__(self, name, age, gender):
        self.name = name
        self.age = age
        self.gender = gender


class OldboyStudent(OldboyPeople):
    """由于学生类没有独自的__init__()方法，因此不需要声明继承父类的__init__()方法，会自动继承"""

    def choose_course(self):
        print('%s is choosing course' % self.name)


class OldboyTeacher(OldboyPeople):
    """由于老师类有独自的__init__()方法，因此需要声明继承父类的__init__()"""

    def __init__(self, name, age, gender, level):
        OldboyPeople.__init__(self, name, age, gender)
        self.level = level  # 派生

    def score(self, stu_obj, num):
        print('%s is scoring' % self.name)
        stu_obj.score = num


stu1 = OldboyStudent('tank', 18, 'male')
tea1 = OldboyTeacher('nick', 18, 'male', 10)

print(stu1.__dict__)

{'name': 'tank', 'age': 18, 'gender': 'male'}

print(tea1.__dict__)

{'name': 'nick', 'age': 18, 'gender': 'male', 'level': 10}

Derived Method Two

• Find strict since the inherited property relations

• super () you will get a special object that is designed to (in accordance with the inheritance relationship) property to access the parent class

• super () .__ init __ (self not to pass by value)

• Full use of super is super (name your own class, self), you need to write complete in python2, and python3 can be abbreviated as super ()

class OldboyPeople:
    school = 'oldboy'

    def __init__(self, name, age, sex):
        self.name = name
        self.age = age
        self.sex = sex


class OldboyStudent(OldboyPeople):
    def __init__(self, name, age, sex, stu_id):
        # OldboyPeople.__init__(self,name,age,sex)
        # super(OldboyStudent, self).__init__(name, age, sex)
        super().__init__(name, age, sex)
        self.stu_id = stu_id

    def choose_course(self):
        print('%s is choosing course' % self.name)


stu1 = OldboyStudent('tank', 19, 'male', 1)

print(stu1.__dict__)

{'name': 'tank', 'age': 19, 'sex': 'male', 'stu_id': 1}