python学习笔记7.更加抽象

Posted 2020-10-02

【python学习笔记】7.更加抽象

• 类的定义就是执行代码块
• 在内存保存一个原始实例，可以通过类名来访问
• 类的实例化，是创建一个原始实例的副本, 并且所有成员变量与原始实例绑定
• 通过修改实例变量，可以解除与原始实例的绑定
• self表示当前实例的引用
• 成员变量也称为特性
• __bases__: 基类
• __class__: 对象类型
• __dict__: 所有特性
• python的接口不用显式的制定对象必须包含哪些方法，只要对象符合当前接口就可以调用
• 可以对象上通过赋值的方式，创建变量

#!/usr/bin/env python
# -*- coding: utf-8 -*-   # 指定源码文件编码,python默认为ASCII

__metaclass__ = type  # 确定使用新式类

class Person:
    def setName(self, name): # self 为是当前实例的引用
        self.name = name
    def getName(self):
        return self.name
    def greet(self):
        print "hello, world! I‘m %s." % self.name
    def __inaccessible(self): # 私有函数，外界不可以访问
        print "Bet you can‘t see me..."
    def _inaccessible(self):  # 不会被import导出
        print "Bet you can‘t see me..."

foo = Person() # 创建对象
bar = Person()

foo.setName("foo")
bar.setName("bar")

print foo.getName()
print bar.getName()

foo.greet()
bar.greet()

#foo.__inaccessible()
foo._inaccessible()


print "------------------------"

‘‘‘
‘‘‘


class MemberCounter:
    print "class MemberCounter begin defined"
    members = 0
    members2 = 0
    def init(self):
        MemberCounter.members += 1
        MemberCounter.members2 += 1


m1 = MemberCounter()
m1.init()
m2 = MemberCounter()
m2.init()

print "----"
print "m1.members", m1.members
print "m2.members", m2.members
print "MemberCounter.members", MemberCounter.members
print "----"


print "modify m1.members"
m1.members=‘m1‘

print "----"
print "m1.members", m1.members
print "m2.members", m2.members
print "MemberCounter.members", MemberCounter.members
print "----"


print "modify MemberCounter.members"
MemberCounter.members = "MemberCounter"

print "----"
print "m1.members", m1.members
print "m2.members", m2.members
print "MemberCounter.members", MemberCounter.members
print "----"

print "create m3"
m3=MemberCounter()
print "----"
print "m1.members", m1.members, "m1.members2", m1.members2
print "m2.members", m2.members, "m2.members2", m2.members2
print "m3.members", m3.members, "m3.members2", m3.members2
print "MemberCounter.members", MemberCounter.members, "MemberCounter.members2", MemberCounter.members2
print "----"


print "modify MemberCounter.members2"
MemberCounter.members2= "members2"

print "----"
print "m1.members", m1.members, "m1.members2", m1.members2
print "m2.members", m2.members, "m2.members2", m2.members2
print "m3.members", m3.members, "m3.members2", m3.members2
print "MemberCounter.members", MemberCounter.members, "MemberCounter.members2", MemberCounter.members2
print "----"


m3.members2="m3.members2"
MemberCounter.members2= "members2 last"

print "----"
print "m1.members", m1.members, "m1.members2", m1.members2
print "m2.members", m2.members, "m2.members2", m2.members2
print "m3.members", m3.members, "m3.members2", m3.members2
print "MemberCounter.members", MemberCounter.members, "MemberCounter.members2", MemberCounter.members2
print "----"



‘‘‘
‘‘‘

print "---------------------"

class Filter:
    def init(self):
        self.blocked = [] # 创建成员变量
    def filter(self, sequence):
        return [x for x in sequence if x not in self.blocked]

class SPAMFilter(Filter): # 继承，可以是逗号分隔的多个基类
    def init(self): # 重载
        self.blocked = [‘SPAM‘]


f = Filter()
f.init()
print f.filter([1,2,3])

s = SPAMFilter()
s.init()
print s.filter(["SPAM", "SPAM","SPAM","SPAM",  "eggs", "bacom" ])




print "---------------------"
class C:
    def dis(self):
        self.c=1
        print self.c

c=C()
c.dis()
c.cc=3
print "c.cc", c.cc

print "c.__dict__", c.__dict__
print "C.__dict__", C.__dict__


print "Filter.__dict__", Filter.__dict__
print "f.__dict__", f.__dict__
print "s.__dict__", s.__dict__

print "m1.__dict__", m1.__dict__
print "m2.__dict__", m2.__dict__
print "m3.__dict__", m3.__dict__
print "MemberCounter.__dict__", MemberCounter.__dict__