Use of Python class inheritance

#!/usr/bin/python
# Filename: inherit.py

class SchoolMember:
    '''Represents any school member.'''
    def __init__(self, name, age):
        self.name = name
        self.age = age
        print'(Initialized SchoolMember: %s)'% self.name

    def tell(self):
        '''Tell my details.'''
        print'Name:"%s" Age:"%s"'% (self.name, self.age),

class Teacher(SchoolMember):
    '''Represents a teacher.'''
    def__init__(self, name, age, salary):
        SchoolMember.__init__(self, name, age)
        self.salary = salary
        print'(Initialized Teacher: %s)'% self.name

    def tell(self):
        SchoolMember.tell(self)
        print'Salary: "%d"'% self.salary

class Student(SchoolMember):
    '''Represents a student.'''
    def __init__(self, name, age, marks):
        SchoolMember.__init__(self, name, age)
        self.marks = marks
        print'(Initialized Student: %s)'% self.name

    def tell(self):
        SchoolMember.tell(self)
        print'Marks: "%d"'% self.marks

t = Teacher('Mrs. Shrividya',40,30000)
s = Student('Swaroop',22,75)
members = [t, s]
for member in members:
    member.tell()# works for both Teachers and Students

(SourceFile: Code/inherit. py)

Output

$ python inherit.py
(Initialized SchoolMember: Mrs. Shrividya)
(Initialized Teacher: Mrs. Shrividya)
(Initialized SchoolMember: Swaroop)
(Initialized Student: Swaroop)

Name:"Mrs. Shrividya" Age:"40" Salary: "30000"
Name:"Swaroop" Age:"22" Marks: "75"

How it works

To use inheritance, we use the basic class name as a tuples after the class name when defining the class. Then, we noticed__init__Dedicated useselfTo initialize the basic class of the object. This is important at 01:10 -- Python does not automatically call the constructor of the basic class. You have to call it in person.

We also observe that we add the class name prefix before the method call, and thenselfVariables and other parameters are passed to it.

Note that when we useSchoolMemberClasstellWhen usingTeacherAndStudentOnlySchoolMember.

In addition, in this example, we calltellInsteadSchoolMemberClasstellMethod. It can be understood that python always finds the corresponding type of method first, which is the case in this example. If it cannot find the corresponding method in the export class, it will start to search for it one by one in the basic class. The basic class is specified in the tuples when the class is defined.

Annotation of a term -- if more than one class is listed in the inherited tuples, it is calledMulti-Inheritance.