新式类 VS 经典类

继承方式的区别：
（新式类用的多）
新式类：

class SonClass(object):
　　super(SonClass,self).__init__(self,name,age,...)

经典类：

class Son:
　　ParentClass.__init__(self,name,age,...)

类的继承：从父类（基类）中继承，可复用已有代码
继承特点：
总是从某个类继承，没有合适父类时从object类继承；
代码饭粒1：

#!/usr/bin/env python
# -*- coding: utf-8 -*-
class A(object):
    def __init__(self,name,age):
        self.name = name
        self.age = age
        self.sex = 'woman'
    def aa(self):
        print('in the aa...')

class B(A):
    def __init__(self,name,age,sex):
        A.__init__(self,name,age)
        print(self.name,self.age,self.sex)
    def aa(self):
        print("in the ba...")
    def bb(self):
        print('in the bb...')

b = B('rose','22','girl')
b.aa()

# 输出：
rose 22 woman
in the ba...

多继承

#!/usr/bin/env python
# -*- coding: utf-8 -*-
class SchoolMenber(object):
    '''学校成员基类'''
    number = 0
    def __init__(self,name,age):
        self.name = name
        self.age = age
        self.enroll()
    def enroll(self):
        print("%s is enrolling..." % self.name)
        SchoolMenber.number += 1
    def tell(self):
        print('-------%s info-----' % self.name)
        for k,v in self.__dict__.items():
            print('\t',k,v)
        print('--------end--------')
    def __del__(self):
        print("%s is dismissed." % self.name)
        SchoolMenber.number -= 1
class School(object):
    def address(self,addr):
        print("You are teaching in %s." % addr)

class Teacher(SchoolMenber,School):
    def __init__(self,name,age,salary,course):
        super(Teacher,self).__init__(name,age)
        self.salary = salary
        self.course = course
    def teaching(self):
        print("%s is teaching %s" % (self.name,self.course))

class Student(SchoolMenber):
    def __init__(self,name,age,course,fee):
        SchoolMenber.__init__(self,name,age)
        self.course = course
        self.fee = fee
    def pay_fee(self,amount):
        print("%s has just paied %s" % (self.name,amount))
        self.amount += amount

t1 = Teacher('Alex',29,9999,'python')
s1 = Student('fone',23,'python',6500)
s2 = Student('lqw',21,'python',6000)
print(SchoolMenber.number)
t1.tell()
s1.tell()
del s2
print(SchoolMenber.number)
t1.address('GD')

多继承时的继承顺序

示例代码：

#!/usr/bin/env python
# -*- coding: utf-8 -*-
class A(object):
    def __init__(self):
        print('A...')
class B(A):
    def __init__(self):
        print('B...')
class C(A):
    def __init__(self):
        print('C...')
class D(B,C):
    def __init__(self):
        print('D...')

D()

继承关系及继承顺序：广度查询

在python3中，无论是新式类还是经典类，都是广度查询。
在python2中为深度查询，即先在左边查询到底，不存在再到邮编查询，上栗顺序为D>B>A>C (了解即可)

 

实例间的相互调用：

#!/usr/bin/env python
# -*- coding: utf-8 -*-

class F1:
    def __init__(self,n):
        self.N = n
        print("F1")
class F2:
    def __init__(self,arg1):
        self.a = arg1
        print("F2")
class F3:
    def __init__(self,arg2):
        self.b = arg2
        print("F3")
o1 = F1('alex')
o2 = F2(o1)
o3 = F3(o2)
print(o3.b.a.N)
# 输出：

F1
F2
F3
alex