1本文的意义
如果给已经存在的类添加新的行为，采用继承方案
如果改变已经存在类的行为，采用重写方案
2图解继承、重写与Super
注：上面代码层层关联。super()可以用到任何方法里进行调用，本文只用在了__init__方法中，通过重写和调用super，可以修改所有方法。
上面类的实例化：
3代码验证
class ContactList(list):
def search(self, name):
matching_contacts = []
for contact in self:
if name in contact.name:
matching_contacts.append(contact)
return matching_contacts class Contact:
all_contacts = ContactList()
def __init__(self, name, email):
self.name = name
self.email = email
self.all_contacts.append(self) class Friend(Contact):
def __init__(self, name, email, phone):
super().__init__(name, email)
self.phone = phone contact1 = Contact("Zhang San", "ZhangSan@qq.com")
contact2 = Contact("Li Si", "LiSi@qq.com")
contact3 = Contact("WangWu", "WangWu@qq.com") myFriend1 = Friend("LiLi", "Lili@qq.con", 666666)
myFriend2 = Friend("YueYue", "Yueyue@qq.con", 888888) In [1]: Contact.all_contacts # 列表记录了实例化的5个对象
[<__main__.Contact at 0x22d6a877048>,
<__main__.Contact at 0x22d6a871fd0>,
<__main__.Contact at 0x22d6a877080>,
<__main__.Friend at 0x22d6a8770b8>,
<__main__.Friend at 0x22d6a877160>] In [2]: [c.name for c in Contact.all_contacts.search('Li')]
['Li Si', 'LiLi']
参考：本文参考学习《Python3 Object Oriented Programming》，根据自己理解改编，Dusty Phillips 著