满足低调之心基础七(1)

一，静态方法，类方法，属性方法

1，静态方法

咱们先任意写一个类：

class Dog(object):def __init__(self, name, food):self.NAME = nameself.FOOD = fooddef eat(self):print("The dog \033[31;1m%s\033[0m is eating \033[34;1m%s\033[0m" % (self.NAME, self.FOOD))d = Dog("huahua", "meat")
d.eat()G:\Python38\python.exe G:/Project1/self_taught/week_7/static_method.py
The dog huahua is eating meatProcess finished with exit code 0

这个已经很熟悉了，那么再看

class Dog(object):def __init__(self, name, food):self.NAME = nameself.FOOD = food@staticmethoddef eat(self):print("The dog \033[31;1m%s\033[0m is eating \033[34;1m%s\033[0m" % (self.NAME, self.FOOD))d = Dog("huahua", "meat")
d.eat()

当我们加了个东西呢？运行发现报错了！

G:\Python38\python.exe G:/Project1/self_taught/week_7/static_method.py
Traceback (most recent call last):File "G:/Project1/self_taught/week_7/static_method.py", line 31, in <module>d.eat()
TypeError: eat() missing 1 required positional argument: 'self'Process finished with exit code 1

说呀，eat()少一个参数"self"，纳尼，是不是丈二和尚 —— 摸不着头脑

其实呢，加上了@staticmethod实际上eat()就和类没有什么关系了，只是类下面的一个函数而已。

那我就要获取eat()里的东西呢？

class Dog(object):def __init__(self, name, food):self.NAME = nameself.FOOD = food@staticmethoddef eat():print("The dog \033[31;1m%s\033[0m is eating \033[34;1m%s\033[0m" % ("huanhuan", "fish"))d = Dog("huahua", "meat")
d.eat()G:\Python38\python.exe G:/Project1/self_taught/week_7/static_method.py
The dog huanhuan is eating fishProcess finished with exit code 0

只需要借类名来调用下。

静态方法：只是名义上归类管，实际上已经访问不了类或实例中的任何属性。

2，类方法

在eat()上面加上@classmethod

class Dog(object):def __init__(self, name, food):self.NAME = nameself.FOOD = food@classmethoddef eat(self):print("The dog \033[31;1m%s\033[0m is eating \033[35;1m%s\033[0m" % (self.NAME, "fish"))d = Dog("huahua", "meat")
d.eat()

发现运行后也报错了，报错的最后一句为：AttributeError: type object ‘Dog’ has no attribute ‘NAME’，说Dog类没有"NAME"属性

再改改：

class Dog(object):n = "Tom"  # 类变量def __init__(self, name, food):self.NAME = nameself.FOOD = food@classmethoddef eat(self):print("The dog \033[31;1m%s\033[0m is eating \033[35;1m%s\033[0m" % (self.n, "fish"))d = Dog("huahua", "meat")
d.eat()G:\Python38\python.exe G:/Project1/self_taught/week_7/class_method.py
The dog Tom is eating fishProcess finished with exit code 0

这就是类方法：只能访问类变量，不能访问实例属性

3，属性方法

class Dog(object):def __init__(self, name):self.NAME = name@propertydef eat(self):print("The dog \033[31;1m%s\033[0m is eating \033[34;1m%s\033[0m" % (self.NAME, "fish"))d = Dog("huahua")
d.eat()

运行时会报错，报错内容为：TypeError: ‘NoneType’ object is not callable，说对象不可调用。

那么尝试改变一下

class Dog(object):def __init__(self, name):self.NAME = name@propertydef eat(self):print("The dog \033[31;1m%s\033[0m is eating \033[34;1m%s\033[0m" % (self.NAME, "fish"))d = Dog("huahua")
d.eat  # ()去掉相当于调变量一样G:\Python38\python.exe G:/Project1/self_taught/week_7/attribute_method.py
The dog huahua is eating fishProcess finished with exit code 0

so，属性方法：把一个方法变成一个静态属性

没有括号的话就没法传参数了，不过好像可以赋值，但是不能直接的赋值

class Dog(object):def __init__(self, name):self.NAME = name@propertydef eat(self):print("The dog \033[31;1m%s\033[0m is eating \033[34;1m%s\033[0m" % (self.NAME, "fish"))@eat.setterdef eat(self, sleep):print("\033[36;1m%s\033[0m is sleeping..." % sleep)d = Dog("huahua")
d.eat
d.eat = "pig"G:\Python38\python.exe G:/Project1/self_taught/week_7/attribute_method.py
The dog huahua is eating fish
pig is sleeping...Process finished with exit code 0

假如我想删除呢？

class Dog(object):def __init__(self, name):self.NAME = name@propertydef eat(self):print("The dog \033[31;1m%s\033[0m is eating \033[34;1m%s\033[0m" % (self.NAME, "fish"))@eat.setterdef eat(self, sleep):print("\033[36;1m%s\033[0m is sleeping..." % sleep)d = Dog("huahua")
d.eat
d.eat = "pig"
del d.eat

运行结果会报错，报错内容为：AttributeError: can’t delete attribute，说不能删除属性

假如我就想删掉呢？

class Dog(object):def __init__(self, name):self.NAME = name@propertydef eat(self):print("The dog \033[31;1m%s\033[0m is eating \033[34;1m%s\033[0m" % (self.NAME, "fish"))@eat.setterdef eat(self, sleep):print("%s \033[36;1m%s\033[0m is sleeping..." % (self.NAME, sleep))@eat.deleterdef eat(self):del self.NAMEprint("deleted")d = Dog("huahua")
d.eat
d.eat = "pig"
del d.eatG:\Python38\python.exe G:/Project1/self_taught/week_7/attribute_method.py
The dog huahua is eating fish
huahua pig is sleeping...
deletedProcess finished with exit code 0

然后我们再查看

class Dog(object):def __init__(self, name):self.NAME = name@propertydef eat(self):print("The dog \033[31;1m%s\033[0m is eating \033[34;1m%s\033[0m" % (self.NAME, "fish"))@eat.setterdef eat(self, sleep):print("%s \033[36;1m%s\033[0m is sleeping..." % (self.NAME, sleep))@eat.deleterdef eat(self):del self.NAMEprint("deleted")d = Dog("huahua")
d.eat
d.eat = "pig"
del d.eat
d.eat

运行报错，报错内容为：AttributeError: ‘Dog’ object has no attribute ‘NAME’，说Dog类没有"NAME"这个属性，说明删除成功！

满足低调之心基础七(1)相关推荐

满足低调之心基础十六
一些css基础内容补充
C++学习基础七——深复制与浅复制
C++学习基础七--深复制与浅复制一.深复制与浅复制基本知识深复制和浅复制,又称为深拷贝和浅拷贝. 深复制和浅复制的区别如下图1所示: 图1 图1表示的是,定义一个类CDemo,包含int a和c ...
JAVA基础七类和对象
文章目录 JAVA基础七类和对象 01 引用 02 继承 03 方法重载 04 构造方法 05 this 06 传参 07 包 08 访问修饰符 09 类属性 10 类方法 11 属性初始化 12 ...
视频教程-PHP零基础七天入门视频课程(免费50章)-PHP
PHP零基础七天入门视频课程(免费50章) 04年进入计算机行业.拥有6年net和php项目开发经验,8年java项目开发经验. 现前端全栈工程师,主攻产品设计,微信开发等. 黄菊华 ¥159.00 ...
Pascal基础(七)-Pascal泛型
Pascal基础(七)-Pascal泛型前言目前很多语言都有泛型或者类似实现 C语言比较古老,没有泛型实现 C++ 有template来实现,个人对c++不懂,应该template和泛型不一样 j ...
Cocos Shader入门基础七：一文彻底读懂深度图。
开篇经过一段时间的持续输出,社区中越来越多的人踏上了3D图形渲染学习之旅,麒麟子非常开心,说明输出的内容对大家都产生了实际的帮助. 特别是上一篇 <用实时反射Shader增强画面颜值> ...
javaWeb基础七天内容笔记汇总
今日内容: 1. web相关概念回顾 2. web服务器软件:Tomcat 3. Servlet入门学习 web相关概念回顾软件架构 C/S:客户端/服务器端 B/S:浏览器/服务器端资源分类静 ...
java基础(七) 深入解析java四种访问权限
戳上面的蓝字关注我们哦! 精彩内容精选java等全套视频教程精选java电子图书大数据视频教程精选 java项目练习精选引言 Java中的访问权限理解起来不难,但完全掌握却不容易,特别是4 ...
oracle jdbc jar包_Oracle总结之plsql编程（基础七）
紧接基础六,对oracle角色和权限的管理之后,在接下来的几次总结中来就最近工作中用过的plsql编程方面的知识进行总结,和大家分享! 一.plsql块 1.只包括执行部分的plsql块打开输出选项 ...

满足低调之心基础七(1)

一，静态方法，类方法，属性方法

满足低调之心基础七(1)相关推荐

最新文章

热门文章