简明python教程七----面向对象的编程（下）

继承：类之间的类型和子类型关系

代码重用：SchoolMember类被称为 基本类或超类，而Teacher和Student类被称为导出类或者子类

#!/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',,)

s=Student('Swaroop',,)

print #prints a blank line

members = [t,s]

for member in members:

    member.tell()

结果：

(Initialized SchoolMember:Mrs.Shrividya)

(Initialized Teacher:Mrs.Shrividya)

(Initialized SchoolMember:Swaroop)

(Initialized Student:Swaroop)

Name:"Mrs.Shrividya" Age:""

Salary: ""

Name:"Swaroop" Age:""

Marks:""

注意：为了使用继承，把基本类的名称作为一个元组跟在定义类时的类名称之后。

基本类的__init__方法专门使用self变量调用，这样我们就可以初始化对象的基本类部分。

记住：python不会自动调用基本类的constructor,需要亲自专门调用它。