Python面向对象(self参数、封装)

day24

面向对象三大特性：封装

self参数

 class Bar:
     def foo(self, arg):
         print(self, arg)

 x = Bar()
 print(x)

 x.foo(112358)
 print('/////////////////////////////////////////')
 y = Bar()
 print(y)

 y.foo(112)

 #self指调用方法的对象

self指调用方法的对象

执行结果：

<__main__.Bar object at 0x7fae0e065780>
<__main__.Bar object at 0x7fae0e065780> 112358
/////////////////////////////////////////
<__main__.Bar object at 0x7fae0e065828>
<__main__.Bar object at 0x7fae0e065828> 112

Process finished with exit code 0

对象可以存值

 class Bar:
     def foo(self, arg):
         print(self, self.name, self.age, arg)

 x = Bar()
 x.name = 'nizhipeng'
 x.age = 18

 x.foo(1123)

 y = Bar()
 y.name = 'nizsvsd'
 y.age = 20

 y.foo(113)

执行结果:

<__main__.Bar object at 0x7fdadb4f5828> nizhipeng 18 1123

<__main__.Bar object at 0x7fdadb4f5860> nizsvsd 20 113

Process finished with exit code 0

封装（面向对象的三大特性之一）

 class Bar:
     def foo(self, arg):
         print(self.name, self.age, arg)

 obj = Bar()
 #将公共变量封装进对象中
 obj.name = "nizhipeng"
 obj.age = ""
 obj.foo("")

将公共变量封装进对象中，为封装。

nizhipeng 18 112358

Process finished with exit code 0