Python面向对象-学习笔记

1 class Student():
2     name = 'lemon'
3 
4 print(Student.__dict__)
5 print(Student.name)
6 Student.name = 'lemon-Xu'
7 print(Student.name)

创建一个类,并访问属性

Class.__dict__:返回类相关信息
Class.name:设置或返回属性

 1 class Student():
 2     name = 'lemon'
 3 
 4     def say(self,name):
 5         self.name = name
 6         print(self.name)
 7 
 8 
 9 a = Student()
10 
11 a.say('lemon-Xu')
12 
13 Student.say(Student,'lemon-X')

类函数

类函数第一个参数必须传入一个对象
当实例化对象调用时传入自身.如果类对象调用时必须手动传入类对象

 1 class Student():
 2     name = 'lemon'
 3 
 4     def __init__(self,name):
 5         self.name = name
 6 
 7 
 8 a = Student('lemon-Xu')
 9 b = Student('lemon-a')
10 
11 print(a.__dict__)
12 print(b.__dict__)
13 print(Student.__dict__)

构造__init__

__init__(self),建议只写一个,重载请参考:https://www.cnblogs.com/erbaodabao0611/p/7490439.html

 1 class Student():
 2     __name = 'lemon'
 3 
 4     def __init__(self,name):
 5         self.__name = name
 6 a = Student('lemon-X')
 7 try:
 8     print(a.name)
 9 except :
10     print('双下滑线的变量名被更名,所以找不到它,它被改名为_Class__attribute')
11 print(a._Student__name)
12 
13 print(Student._Student__name)

private,__name

被__(双下划线)修饰的属性,会被更名为_Class__attribute
被_(单下划线)修饰的属性,是被保护的属性

 1 class Pepole:
 2     name = 'lemon' # 公共
 3     __age = 18 # 私有
 4     _adr = '百草路' # 受保护
 5 
 6     def __init__(self,name):
 7         self.name = name
 8 
 9     def sleep(self):
10         print('困了睡觉....')
11 
12 class Student(Pepole):
13     def work(self):
14         print("写作业")
15 
16     def sleep(self):
17         self.work()
18         super().sleep()
19 
20 s = Student('lemon')
21 print(Pepole.__dict__)
22 print(Student.__dict__)
23 print(s.__dict__)
24 s.sleep()

extends,单继承

super()方法得到父类

 1 # extends super
 2 
 3 class A():
 4     def __init__(self,name):
 5         print('A')
 6         print(name)
 7 # 第一种
 8 class B(A):
 9     name = 'B'
10     def __init__(self,name):
11         A.__init__(self,name)
12         print('B')
13 
14     def a(self):
15         print('当前类是:',self.name)
16 # 第二种
17 class C(B):
18     name = 'C'
19     def __init__(self,name):
20         super().__init__(name)
21         print('C')
22 
23     def C2(self):
24         super().a()
25 
26 a = A('lemon')
27 print()
28 c = C('lemon')
29 c.C2()
30 
31 
32 run:
33 A
34 lemon
35 
36 A
37 lemon
38 B
39 C
40 当前类是: B

调用父类方法

super().方法,默认传入当前对象

Python面向对象-学习笔记

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