Python Learning Lesson 16 - Static property (property, classmethod, staticmethod)

Calculate the area live in the house

Longhand

class Room:
    def __init__(self,name,owner,width,length,heigh):
        self.name=name
        self.owner=owner
        self.width=width
        self.lenth=length
        self.heigh=heigh

    def cal_area(self):
        print('%s 住的 %s 总面积为 %s' %(self.owner,self.name,self.heigh*self.width))

r1=Room('别墅','憨憨',100,100,100)
r2Room = ( ' Chateau ' , ' Meimei ' , 1000,1000,1000 ) 

r1.cal_area () # Han Han live villa total area of 10000 
r2.cal_area () # Meimei live Chateau total area of 1,000,000

property wording

# Property Usage 
class Room:
     DEF  __init__ (Self, name, owner, width, length, HEIGH): 
        self.name = name 
        self.owner = owner 
        self.width = width 
        self.lenth = length 
        self.heigh = HEIGH 

    the @Property   # decorator property may be converted to the property does not need to call upon the following parentheses 
    DEF cal_area (Self):
         Print ( ' % s% s live total area% s ' % (self.owner, the self.name, Self. * HEIGH self.width)) 


R1 = Room (' Home ' , ' Han Han ' , 100, 100, 100 ) 
R2 = Room ( ' Chateau ' , ' Meimei ' , 1000, 1000, 1000 ) 

r1.cal_area   # Han Han live villa total area of 10000 
R2. cal_area   # Mei Mei lived in a large villa with a total area of 1,000,000

Class method (a classmethod)

class Room:

    tag=1
    def __init__(self,name,owner,width,length,heigh):
        self.name=name
        self.owner=owner
        self.width=width
        self.lenth=length
        self.heigh=heigh
    @property
    def cal_area(self,):

        return self.heigh*self.width

    def test(self,):

        print('from test',self.name)

    @classmethod  # 变为了类方法
    deftell_info (CLS):
         Print (CLS)
         Print ( ' ----> ' , cls.tag) 


    # DEF tell_info (Self): 
    #      Print ( '---->', self.tag) 

Print (Room.tag )   # . 1 
# R1 = Room ( 'Home', 'Han Han', 100,100,100) 
# Room.test ( 'test') 

# Room.tell_info (R1) # ---->. 1 
Room.tell_info () # - -> 1 has cls do not need to instantiate an object of

Static method

class Room:

    tag=1
    def __init__(self,name,owner,width,length,heigh):
        self.name=name
        self.owner=owner
        self.width=width
        self.lenth=length
        self.heigh=heigh
    @property  # 静态属性
    def cal_area(self,):

        return self.heigh*self.width

    def test(self,):

        print('from test',self.name)

    @classmethod  # 变为了类方法
    def tell_info(cls):
        print(cls)
        print('---->', cls.tag)

    @staticmethod  # 静态方法只是名义上归属性管理，不能使用类变量和实例变量，是类的工具包
    def wash_body(a,b,c):
        print('%s %s %s 正在洗澡 '%(a,b,c))

    def test(x,y,z):
        print(x,y,z)


Room.wash_body('k','l','o') # k l o 正在洗澡
r1=Room('别墅','憨憨',100,100,100)
r1.wash_body('k','l','o') # k l o 正在洗澡


Room.test('k','l','o') # k l o
r1.test('k','l','o') # 报错了  不能这样调用  因为test 不是静态方法

静态方法