python静态方法类方法

Posted 2020-10-23 cecelia

常规：

1 class Dog(object):
2     def __init__(self,name):
3         self.name=name
4 
5     def eat(self):
6         print(‘%s is eating‘%self.name)
7 
8 d1=Dog(‘lele‘)
9 d1.eat()

1.静态方法：名义上由类管理，而实际在调用时，需要手动把实例对象传进去作参数

1 class Dog(object):
2     def __init__(self,name):
3         self.name=name
4     @staticmethod
5     def eat(self):
6         print(‘%s is eating‘%self.name)
7 
8 d1=Dog(‘lele‘)
9 d1.eat(d1)

2.类方法：只能访问类变量，不能访问实例变量

 1 class Dog(object):
 2     name=‘xiaomei‘
 3     def __init__(self,name):
 4         self.name=name
 5 
 6     @classmethod
 7     def eat(self):
 8         print(‘%s is eating‘%self.name)
 9 
10 d1=Dog(‘lele‘)
11 d1.eat()

实例变量name=‘lele‘，类变量name=‘xiaomei‘。

调用结果为：xiaomei is eating

3.属性方法：把一个方法变为一个静态属性（用途：用户只需要知道查询结果（调用属性），而复杂的实现过程不需要用户知道。eg:第三方查询航班）

 1 class Dog(object):
 2     def __init__(self,name):
 3         self.name=name
 4 
 5   6     @property
 7     def eat(self):
 8         print(‘%s is eating‘%self.name)
 9 
10 d1=Dog(‘lele‘)
11 d1.eat

lele is eating

若要增加参数，可以通过 @属性方法名.setter  来实现

class Dog(object):
    def __init__(self,name):
        self.name=name
        self.__food=None
    #将一个方法变为静态属性
    @property
    def eat(self):
        print(‘%s is eating %s‘ % (self.name,self.__food))

    #更改属性方法
    @eat.setter
    def eat(self,food):   #增加了参数
        self.__food=food
        print(‘%s is eating %s‘ % (self.name, self.__food))
    #删除属性方法
    @eat.deleter
    def eat(self):
        del self.__food
        print(‘已删除‘)

d1=Dog(‘lele‘)
d1.eat
d1.eat=‘gutou‘   #变成静态属性后，注意赋值方式
d1.eat
del d1.eat

lele is eating None
lele is eating gutou
lele is eating gutou
已删除