089 reuse parent class method in two ways

Reuse the parent class method in two ways:

1. Use naming names directly call the method specified class
2. super keyword

A direct call method specified class

• Use naming names, and nothing to do with inheritance. But it needs to complete

class Person:
    school = 'xxx'
    def __init__(self,name,age):
        self.name=name
        self.age=age
    def study(self):
        print('study....')

class Student(Person):
    school = 'yyyy'
    def __init__(self,name,age,course):
        # 直接调用Person类的__init__方法
        Person.__init__(self,name,age)
        self.course=course
    def study(self):
        Person.study(self)
        print("%s学生在学习"%self.name)
        
stu1=Student('wed',19,"Python")
# stu1.school='xxx'
print(stu1.school)
stu1.study()

yyyy
Study ....
Wed students in learning

Second, through the super () keyword

First of all, super () method is used to call a parent class (super class)

Its calling sequence is according to the calling object mro call sequence () method .

2.1 Use

super () method is used, and in python2 python3 are not the same.

• The new class of writing:

  super().__init__(参数1，参数2) # 新式类，调用父类的init方法并传参

• Classic wording:

  super(当前类名,self).__init__(参数1，参数2) # 经典类，调用父类的init方法并传参

2.2 use super to call the parent class method

class Person(object):
    school = 'xxx'
    def __init__(self,name,age):
        self.name=name
        self.age=age
    def study(self):
        print('study....')

class Student(Person):
    school = 'yyyy'
    def __init__(self,name,age,course):
        #super() 会按照mro列表拿到父类对象
        #对象来调用绑定方法,不需要传递第一个参数(self)
        super().__init__(name,age)
        #经典类和新式类
        #经典类中必须这么写(py3中没有经典类),都用上面那种方式写
        # super(Student,self).__init__(name,age)
        self.course=course
    def study(self):
        # Person.study(self)
        super().study()
        # print("%s学生在学习"%self.name)


stu1=Student('wed',19,"Python")
# stu1.school='xxx'
# print(stu1.school)
stu1.study()

2.3 super () call to order

Keep in mind: it is a sequence of calls to call the calling sequence of objects mro () method .

# super是按照mro列表找
class A:
    def f1(self):
        print('A.f1')
class B:
    def f1(self):
        print('B.f1')
    def f2(self):
        print('B.f2')

        # 重点
        super().f1()


class C(B,A):
#注意这个顺序,这个顺序报错
# class C(A,B):
    def f1(self):
        print('C.f1')

#C实例化产生一个对象
c=C()
# print(c.f2())
print(C.mro())
c.f2()

[<class 'main.C'>, <class 'main.B'>, <class 'main.A'>, <class 'object'>]
B.f2
A.f1