[python3]: python --【class】类变量（类属性）

[python3]:  python  --【class】类变量（类属性）

一、说明：

　　1、类变量：类变量，定义在【类内】且【函数外】。

 1 class  object:
 2 
 3     #  class_variable
 4     icount    =    0
 5 
 6 
 7     def  __init__(self):
 8         #    using  class_variable
 9         object.icount    =    object.icount  +  1
10 
11 
12     def  objnum(self):
13         print(f"object_number := { object.icount }")

　　2、类变量的使用方法：class_name.class_variable

　　　　2.1、object.icount:：

　　　　　　2.1.1：class_name = object

　　　　　　2.1.2：class_variable  =  icount

二、代码

 1 #!/usr/bin/env python3
 2 
 3 
 4 class object:
 5 
 6     #  variable of class(class_variable)
 7     #  using variable of class:  object.icount (class_name.class_variable)
 8     icount = 0
 9 
10     def __init__(self, name):
11         self.icount = 1
12         self.__objname =  name
13         object.icount = object.icount + 1
14         print(f"[constructor]#  object_name:{ self.__objname },    object.icount = { object.icount } ")
15 
16     def __del__(self):
17         object.icount = object.icount - 1
18         print(f"[destructor]#  object_name:{ self.__objname },    object.icount = { object.icount } ")
19 
20     def object_number(self):
21         print(f"\nobject_number := { object.icount }")
22         print(f"self_icount := { self.icount } \n")
23 
24     def msg_name(self):
25         print(f"name := { self.__objname }")
26 
27 
28 if __name__ == '__main__':
29     x1 = object("f1")
30     x2 = object("f2")
31     x3 = object("f3")
32     x4 = object("f4")
33 
34     x1.object_number()
35     x2.object_number()
36     x3.object_number()
37     x4.object_number()

三、运行结果

 1 [constructor]#  object_name:f1,    object.icount = 1 
 2 [constructor]#  object_name:f2,    object.icount = 2 
 3 [constructor]#  object_name:f3,    object.icount = 3 
 4 [constructor]#  object_name:f4,    object.icount = 4 
 5 
 6 object_number := 4
 7 self_icount := 1 
 8 
 9 
10 object_number := 4
11 self_icount := 1 
12 
13 
14 object_number := 4
15 self_icount := 1 
16 
17 
18 object_number := 4
19 self_icount := 1 
20 
21 [destructor]#  object_name:f1,    object.icount = 3 
22 [destructor]#  object_name:f2,    object.icount = 2 
23 [destructor]#  object_name:f3,    object.icount = 1 
24 [destructor]#  object_name:f4,    object.icount = 0 

四、参考内容

　　1、　　Python3 面向对象　　--　　https://www.runoob.com/python3/python3-class.html