day18-1 面向对象进阶

1.静态方法

class Dog(object):
    def __init__(self,name):
        self.name = name

    @staticmethod    #静态方法实际上和类没有关系，也是一个装饰器，
    def eat(self):  # 这时候eat函数在类里面，但是类不向其传参数,这时候要调用传参数可以把实例化的类传进去
        print("%s is eating %s" %(self.name,"qq"))
d = Dog("ABc")
d.eat(d)
# 静态方法
#只是名义上归类管理，实际上静态方法访问不了任何类的任何属性和方法

2.类方法

class Dog(object):
    name = 'ABDc'
    def __init__(self,name):
        self.name = name

    @classmethod  #直接调用显示没有name.类方法只能访问类变量，不能访问实例变量。特定场景，类变量和实例变量相同，某个方法只能访问类变量，就可以使用类方法
    def eat(self):
        print("%s is eating %s" %(self.name,"qq"))
d = Dog("ABc")
d.eat()

3.属性方法

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

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

    def talk(self):
        print("%s talking %s" %(self.name,"oneone"))

    @property   # 属性方法传参数
    def eat1(self):
        print("%s is eating %s" %(self.name,self.__food))

    @eat1.setter   # 属性方法传参数
    def eat1(self,food):
        print("seet to food:",food)
        self.__food = food    # 把传入的参数存入实例化变量

    @eat1.deleter
    def eat1(self):
        del self.__food
        print("删完了")

d = Dog("ABc")
d.eat  # 属性方法把一个方法变成静态属性
d.talk()
d.eat1 = "鸡蛋"
d.eat1
# del d.eat1    # 属性方法不能直接删除
del d.eat1

# ABc is eating qq
# ABc talking oneone
# seet to food: 鸡蛋
# ABc is eating 鸡蛋
# 删完了

4.属性方法的用处

class Flight(object):
    def __init__(self,name):
        self.flight_name = name


    def checking_status(self):
        print("checking flight %s status " % self.flight_name)
        return  1

    @property
    def flight_status(self):
        status = self.checking_status()
        if status == 0 :
            print("flight got canceled...")
        elif status == 1 :
            print("flight is arrived...")
        elif status == 2:
            print("flight has departured already...")
        else:
            print("cannot confirm the flight status...,please check later")

    @flight_status.setter

    def flight_status(self,status):
        print("%s has changing %s" %(self.flight_name,2))


f = Flight("CA980")
f.flight_status
f.flight_status = 2

# checking flight CA980 status
# flight is arrived...
# CA980 has changing 2

5.类的特殊成员方法

__doc__

class Dog(object):
    '''描述狗这个对象'''
    name = 'ABDc'
    def __init__(self,name):
        self.name = name


    def eat(self):
        print("%s is eating %s" %(self.name,"qq"))
d = Dog("ABc")
print(Dog.__doc__)

# 描述狗这个对象

2.__call__

class Dog(object):
    name = 'ABDc'
    def __init__(self,name):
        self.name = name

    def eat(self):
        print("%s is eating %s" %(self.name,"qq"))

    def __call__(self, *args, **kwargs):
        print("runing Call",args,kwargs)
class Dog(object):
    name = 'ABDc'
    def __init__(self,name):
        self.name = name

    def eat(self):
        print("%s is eating %s" %(self.name,"qq"))
d = Dog("ABc")
d.eat()
d = Dog("aDSF")
d(1,2,3,name='ss')#  对象后面加（），也可以类（）（）

3.__dict__

class Dog(object):
    name = 'ABDc'
    def __init__(self,name):
        self.name = name

    def eat(self):
        print("%s is eating %s" %(self.name,"qq"))

    def __call__(self, *args, **kwargs):
        print("runing Call",args,kwargs)
print(Dog.__dict__)  #打印类里面所有属性，不包括实例属性
d = Dog("aDSF")
print(d.__dict__)   # 打印实例属性

4.__str__

class Dog(object):
    name = 'ABDc'
    def __init__(self,name):
        self.name = name

    def eat(self):
        print("%s is eating %s" %(self.name,"qq"))

    def __call__(self, *args, **kwargs):
        print("runing Call",args,kwargs)

    def __str__(self):
        return "<obi:%s>"%self.name
d  = Dog('asdd')
print(d)
#<obi:asdd>

5.

class Foo(object):
    def __init__(self):
        self.data = {}
    #用于索引操作，如字典，以下分别表示获取，设置，删除数据

    def __getitem__(self,key):
        print("__getitem__",key)
        return self.data.get(key)

    def __setitem__(self, key, value):
        print("__setitem__",key,value)
        self.data[key] = value

    def __delitem__(self, key):
        print("__delitem__",key)

obj = Foo()
obj['name'] = 'abc'
print(obj['name'])
print(obj.data)
del obj['name']

6.type

# class Foo(object):
#     def __init__(self,name):
#         self.name = name
#
# f = Foo("abc")
# print(type(f))
# print(type(Foo))    # 普通方式创建类

def func(self):
    print("hello %s" %self.name )

def __init__(self,name,age):
    self.name = name
    self.age = age

Foo =type('Foo',(object,),{'func':func,
                           '__init__':__init__})
f = Foo('china','1000000000')
f.func()
print(type(Foo))

# hello world
# <class 'type'>

6.__new__ 先于__init__以后看