Python中的继承

派生类继承形式为：class DerivedClass(BaseClass):



[注意]

[1] Python不会自动调用基类的constructor，我们要亲自专门调用它。在方法调用之前加上类名前缀，然后把self变量及其他参数传递给它。

[2] Python总是首先查找对应类型的方法，如果它不能在派生类中找到对应的方法，它才开始到基类中查找。

[3] 基类是在派生类定义的时候，在元组之中指明的。

[4] 如果在继承元组中列了一个以上的类，那么它就被称作多重继承。

#! /usr/bin/python
# Filename: inherit.py
# 2010-7-14 wcdj
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), # note, this comma
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('Mr. Young', 40, 30000)
s=Student('wcdj', 22, 75)
print # prints a blank line
members=[t, s]
for i in members:
        i.tell() # works for both Teachers and Students
#########
# output
#########
>>> 
(Initialized SchoolMember:Mr. Young)
(Initialized Teacher:Mr. Young)
(Initialized SchoolMember:wcdj)
(Initialized Student:wcdj)
Name:"Mr. Young" Age:"40" Salary:"30000"
Name:"wcdj" Age:"22" Marks:"75"