Python Programming - Object Oriented Programming: Inheritance

Inheritance is designed for code reuse and design reuse

In the inheritance relationship, the existing and designed classes are called parent classes or base classes, and the newly designed classes are called subclasses or derived classes

A derived class can inherit the public members of the parent class, but not its private members

If you need to call the method of the base class in the derived class, you can use the built-in function super() or use the base class name.method name() to achieve

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Python supports multiple inheritance. If there is the same method name in the parent class, but the parent class name is not specified when used in the child class,

then the python interpreter will search sequentially from left to right

#Define base class 
class Person(object):     #Must be based on object 
    def  __init__ (self,name= '' ,age=20,sex= ' man ' ):
        self.setName(name)
        self.setAge(age)
        self.setSex(sex)
        
    def setName(self,name):
        if not isinstance(name,str):
            print('name must be string.')
            return
        self.__name=name
        
    def setAge(self,age):
        if not isinstance(age,int):
            print('age must be integer.')
            return
        self.__age=age
        
    def setSex(self,sex):
        if sex != 'man' and sex != 'woman':
            print('sex must be "man" or "woman".')
            return
        self.__sex = sex
        
    def show(self):
        print('name:',self.__name)
        print('age:',self.__age)
        print('sex:',self.__sex)


#Define the derived class and call the base class method 
class Teacher(Person):
     def  __init__ (self,name= '' ,age=30,sex= ' man ' ,id=215 ):
        super(Teacher,self).__init__(name,age,sex)
        self.setId(id)
        
    def setId(self,id):
        if not isinstance(id,int):
            print('id must bu integer.')
            return
        self.__id = id
    
    def show(self):
        super(Teacher, self).show() #Call     the method of the base class 
        print ()
        
if __name__=='__main__':
    zhangle = Person( ' zhang le ' ,19, ' man ' )
    zhangle.show()
    limu = Teacher( ' li mu ' ,32, ' man ' ,233 )
    limu.show()
    limu.setId( 666 )
    limu.show()

out:

name: zhang le
age: 19
sex: man
name: li mu
age: 32
sex: man

name: li mu
age: 32
sex: man