1. Define a class ( There is no limit to which class is defined )：

requirement : a. You need a class variable
b. Need to have >=2 Multiple object variables
c. Define a method ： Print class variables and object variables
d. Use print Print object -> Output is This is a object
e. Instantiate two objects ： And the sum of two objects equals 2
f. Add a temporary variable to the object temp_var

class Student:
    college = ' Xi'an Peihua college '

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

    def print_info(self):
        print(Student.college)
        print(self.name, self.age)

    def __str__(self):
        return 'This is a object'

    def __add__(self, other):
        return self.age + other.age


stu = Student(' Wang Hailin 1', 28)
stu.print_info()
print(stu)
stu1 = Student(' Wang Hailin 2', 30)
print(stu + stu1)
stu.sex = ' male '
print(stu.sex)

2.super Use :

Define a class A, There's another way print_info
Define a class B, There's a way print_info And a way say_something
Define a class C, There's a way say_something
Define a class D, There's a way print_info And a way say_something
Define a class E, Inheritance class A, class B, class C, class D
Instantiate the class E The object of
perform print_info and say_something Method
utilize super, Let's execute print_info Called when the B in print_info
utilize super, Let's execute say_something Called when the C in say_something
utilize super, Let's execute print_info and say_something Called when the
D in print_info and say_something

class A:
    def print_info(self):
        print(' ahhhh  A')


class B:
    def print_info(self):
        print(' No, no, no, No  B')

    def say_something(self):
        print(' Baba Papa  B')


class C:
    def say_something(self):
        print(' Melancholy long Cen long  C')


class D:
    def print_info(self):
        print(' It's true  D')

    def say_something(self):
        print(' Every bit of  D')


class E(C, D, A, B):
    def print_info(self):
        #  utilize super, Let's execute print_info Called when the B in print_info
        # super(A, self).print_info()
        #  utilize super,  Let's execute print_info and say_something Called when the D in print_info and say_something
        super(C, E).print_info(self)

    def say_something(self):
        #  utilize super,  Let's execute say_something Called when the C in say_something
        # super().say_something()
        super(C, E).say_something(self)


e = E()
e.print_info()
e.say_something()
print(E.__mro__)

3. Define a parent class and a subclass ：

requirement ： Contains three object variables , And one of the object variables uses _ name
Define a method ： After using __ name
Define a subclass to inherit the upper parent class ： And define a method with the same name as the parent method (__)
Instantiate subclass objects
Access band _ Object variables for
Access... In the parent class __xxx Method
Access... In the subclass __xxx Method

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

    def __print_info(self):
        print(self.age)


class Student(Person):
    def __print_info(self):
        print(self.name)


stu = Student(' Zhang San ', 12, ' male ')
print(stu._sex)
stu._Person__print_info()
stu._Student__print_info()