Python学习记录七---继承、多态和封装

1、创建类

  创建文件 test7.py
  #! /usr/bin/env python
  class Person:

    def setName(self, name):
      self.name = name
    def getName(self):
      return self.name
    def greet(self):
      print "hello, world! I am %s."% self.name

foo = Person()
foo.setName('yilia')
foo.getName()
foo.greet()

2、特性、函数、方法
  私有变量: 只要在它的名字前面加上双下划线即可:
    class Secretive:

      def __inaccessible(self):
        print "bet you can't see me"

      def accessible(self):
        print "this secret message is:"
        self.__inaccessible() # 内部调用私有方法

s = Secretive()
s.accessible()
s.__inaccessible() #外部调用私有方法

3、类的命名空间

    >>> class Counter:
    ...   b = 0
    ...   def init(self):
    ...    self.b += 1
    ...
    >>> num1 = Counter()
    >>> num1.init()
    >>> Counter.b
    0
    >>> num1.init()
    >>> Counter.b
    0
    >>> num1.b
    2
    >>> num2 = Counter()
    >>> num2.init()
    >>> Counter.b
    0
    >>> num2.b
    1

4、指定超类 将其它类名写在class语句后的圆括号内可以指定超类, 多个超类用“,”分隔

  (1) 使用超类
    class Filter:
      def init(self):
        self.blocked = []
      def filter(self, sequence):
        return [x for x in sequence if x not in self.blocked]

    class SPAMFilter(Filter):
      def init(self):
        self.blocked = ['SPAM']

(2) 查看一个类是否是另一个类的子类,使用issubclass
    >>> isSubclass(SPAMFilter, Filter)
    Ture
    >>> isSubclass(Filter, SPAMFilter)
    False

(3) 如果想要知道一个类的基类(们), 可以使用它的特殊属性 __bases__
    >>> class Counter:
    ...   b = 0
    ...   def init(self):
    ...    self.b += 1
    ...

    >>> Counter.__bases__
    ()

    >>> class AddCounter(Counter):
    ...    def init(self):
    ...    print "this is subClass"
    ...
    >>> issubclass(AddCounter, Counter)
    True
    >>> AddCounter.__bases__
    (<class __main__.Counter at 0x7fcd9b5db328>,)
    >>>

5、接口和内省

原文地址:https://www.cnblogs.com/songshu-yilia/p/5239681.html