1.靜態方法：只是名義上歸類管理，實際上在靜態方法裏訪問不了類或實例中的任何屬性。相當於類的工具包。

class Dog(object):
    def __init__(self,name):
        self.name=name
    @staticmethod  #實際上跟類沒什麽關系了，相當於一個獨立的函數。
    def eat(self,food):
        print("%s is eating %s"%(self.name,food))

    def drink(self,food):
        print("%s is drinking %s"%(self.name,food))

d1=Dog("Lily")
d1.drink("Cooola")  #drink正常執行
d1.eat("baozi") #靜態方法

運行結果：

Traceback (most recent call last):
  File "<encoding error>", line 13, in <module>
TypeError: eat() missing 1 required positional argument: ‘food‘
Lily is drinking Cooola

2.類方法只能訪問類變量，不能訪問實例變量。

class Dog(object):
    n=123
    def __init__(self,name):
        self.name=name
    @classmethod  #類方法，被修飾的下列函數只能訪問類變量，不能訪問實例變量。
 
    def eat(self,food):
        print("類變量%s" % self.n)
        print("%s is eating %s"%(self.name,food))

    def drink(self,food):
        print("%s is drinking %s"%(self.name,food))

d1=Dog("Lily")
d1.drink("Cooola")  #drink正常執行
d1.eat("baozi") #類方法

運行結果：

Lily is drinking Cooola
類變量123
Traceback (most recent call last):
  File "<encoding error>", line 15, in <module>
  File "<encoding error>", line 8, in eat
AttributeError: type object ‘Dog‘ has no attribute ‘name‘

3.屬性方法

把一個方法變成一個靜態屬性。隱藏實現細節。就不能加（）調用了。給屬性方法賦值

class Dog(object):

    def __init__(self,name):
        self.name=name
        self.__food=None

    @property  #屬性方法
    def eat(self):
        print("%s is eating %s"%(self.name,self.__food))

    @eat.setter
    def eat(self,food):
        print("set to food:",food)
        self.__food=food

d=Dog("Lily")
d.eat
d.eat="baozi" #屬性方法
d.eat

運行結果：

Lily is eating None
set to food: baozi
Lily is eating baozi

4.屬性方法在實例中不能以del d.eat 的方式刪除。刪除方法如下：

class Dog(object):

    def __init__(self,name):
        self.name=name
        self.__food=None

    @property  #把一個方法變成屬性
    def eat(self):
        print("%s is eating %s"%(self.name,self.__food))

    @eat.setter  #修改它
    def eat(self,food):
        print("set to food:",food)
        self.__food=food

    @eat.deleter  #刪除它
    def eat(self):
        del self.__food
        print("刪除完畢")

d=Dog("Lily")
d.eat
d.eat="baozi" #屬性方法
d.eat
del d.eat
d.eat

運行結果：

Lily is eating None
set to food: baozi
Lily is eating baozi
刪除完畢
Traceback (most recent call last):
  File "<encoding error>", line 26, in <module>
  File "<encoding error>", line 9, in eat
AttributeError: ‘Dog‘ object has no attribute ‘_Dog__food‘

靜態方法，類方法，屬性方法