组合补充、主动调用其他类的成员、特殊成员

一、组合补充

　　1.类或对象是否能做字典中的key

class Foo:
    pass

dic = {
    Foo:1,
    Foo():2
}
print(dic)
#{<class '__main__.Foo'>: 1, <__main__.Foo object at 0x000001BD743A8BA8>: 2}　　#很明显是可以做字典的key的

　　2.对象中到底有什么(*)

class Foo:

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

    def dispaly(self):
        print(self.age)

data_list = [Foo(8),Foo(9)]
for el in data_list:
    print(el.age,el.dispaly())
# 8　　　　　　　　　　　　　　　　　　这个8是在print语句中的el.display()执行的结果，
# 8 None　　　　　　　　　　　　　　　这个8是print语句中el.age的值，None是el.display()没有返回值
# 9
# 9 None

　　3.

class StarkConfig(object):

    def __init__(self,num):
        self.num = num

    def changelist(self,request):
        print(self.num,request)

class RoleConfig(StarkConfig):

    def changelist(self,request):
        print('666')
config_obj_list = [StarkConfig(1),StarkConfig(2),RoleConfig(3)]
for item in config_obj_list:
    print(item.num)　　#item.num其实就是StarkConfig(1).num
# 1
# 2
# 3

　　4.

class StarkConfig(object):

    def __init__(self,num):
        self.num = num

    def changelist(self,request):
        print(self.num,request)

class RoleConfig(StarkConfig):
    pass

config_obj_list = [StarkConfig(1),StarkConfig(2),RoleConfig(3)]
for item in config_obj_list:
    item.changelist(168)
# 1 168
# 2 168
# 3 168

　　5.

class StarkConfig(object):

    def __init__(self,num):
        self.num = num

    def changelist(self,request):
        print(self.num,request)

class RoleConfig(StarkConfig):

    def changelist(self,request):
        print(666,self.num)

config_obj_list = [StarkConfig(1),StarkConfig(2),RoleConfig(3)]
for item in config_obj_list:
    item.changelist(168)
# 1 168
# 2 168
# 666 3

　　6.

class StarkConfig(object):

    def __init__(self,num):
        self.num = num

    def changelist(self,request):
        print(self.num,request)

    def run(self):
        self.changelist(999)

class RoleConfig(StarkConfig):

    def changelist(self,request):
        print(666,self.num)

config_obj_list = [StarkConfig(1),StarkConfig(2),RoleConfig(3)]
config_obj_list[1].run()
config_obj_list[2].run()
# 2 999
# 666 3

　　7.

class StarkConfig(object):

    def __init__(self,num):
        self.num = num

    def changelist(self,request):
        print(self.num,request)

    def run(self):
        self.changelist(999)

class RoleConfig(StarkConfig):

    def changelist(self,request):
        print(666,self.num)


class AdminSite(object):
    def __init__(self):
        self._registry = {}

    def register(self,k,v):
        self._registry[k] = v

site = AdminSite()
print(len(site._registry)) #0
site.register('range',666)
site.register('shilei',438)
print(len(site._registry)) #2
site.register('lyd',StarkConfig(19))
site.register('yjl',StarkConfig(20))
site.register('fgz',RoleConfig(33))
print(len(site._registry)) #5

　　8.

class StarkConfig(object):

    def __init__(self,num):
        self.num = num

    def changelist(self,request):
        print(self.num,request)

    def run(self):
        self.changelist(999)

class RoleConfig(StarkConfig):

    def changelist(self,request):
        print(666,self.num)

class AdminSite(object):
    def __init__(self):
        self._registry = {}

    def register(self,k,v):
        self._registry[k] = v

site = AdminSite()
site.register('lyd',StarkConfig(19))
site.register('yjl',StarkConfig(20))
site.register('fgz',RoleConfig(33))
print(len(site._registry)) # 3

for k,row in site._registry.items():
    row.changelist(5)
# 19 5
# 20 5
# 666 33

　　9.

class StarkConfig(object):

    def __init__(self,num):
        self.num = num

    def changelist(self,request):
        print(self.num,request)

    def run(self):
        self.changelist(999)

class RoleConfig(StarkConfig):

    def changelist(self,request):
        print(666,self.num)

class AdminSite(object):
    def __init__(self):
        self._registry = {}

    def register(self,k,v):
        self._registry[k] = v

site = AdminSite()
site.register('lyd',StarkConfig(19))
site.register('yjl',StarkConfig(20))
site.register('fgz',RoleConfig(33))
print(len(site._registry)) # 3

for k,row in site._registry.items():
    row.run()
# 19 999
# 20 999
# 666 33

　　10.

class UserInfo(object):
    pass

class Department(object):
    pass

class StarkConfig(object):

    def __init__(self,num):
        self.num = num

    def changelist(self,request):
        print(self.num,request)

    def run(self):
        self.changelist(999)

class RoleConfig(StarkConfig):

    def changelist(self,request):
        print(666,self.num)

class AdminSite(object):
    def __init__(self):
        self._registry = {}

    def register(self,k,v):
        self._registry[k] = v(k)

site = AdminSite()
site.register(UserInfo,StarkConfig)
site.register(Department,StarkConfig)
for k,row in site._registry.items():
    row.run()
# <class '__main__.UserInfo'> 999
# <class '__main__.Department'> 999

　　总结：

　　　　1.要知道对象中封装了什么

　　　　2.self到底是谁

二、主动调用其他类的成员

class Base(object):
    def f1(self):
        print("asd")
obj = Base()　　　　#我们在调用类中的方法时，一般都是先创建一个对象，然后用对象名.方法名就可以调用
obj.f1()

obj = Base()　　　　
Base.f1(obj)　　　　#用类名也可以调用类中的方法，但是方法中的self必须手动传入

　　方式一：

class Base(object):
    def f1(self):
        print("asd")

class Foo(Base):
    def f1(self):
        print("qwe")
        Base.f1(self)
obj = Foo()
obj.f1()
# qwe
# asd

　　方式二、 按照类的继承顺序，找下一个

class Base(object):
    def f1(self):
        print("asd")

class Foo(Base):
    def f1(self):
        print("qwe")
        super().f1()
obj = Foo()
obj.f1()
# qwe
# asd

class Bar(object):
    def f1(self):
        print("asd")

class Foo(object):
    def f1(self):
        print("qwe")
        super().f1()  #这里的self是App，按照App继承顺序的下一个是Bar所以调用了Bar中的f1方法

class App(Foo,Bar):
    pass

obj = App()
obj.f1()
# qwe
# asd

三、特殊成员

class Foo(object):

    def __init__(self,a1,a2):
        self.a1 = a1
        self.a2 = a2

    def __call__(self, *args, **kwargs):
        print(111,args,kwargs)
        return 123

    def __getitem__(self, item):
        print(item)
        return 11

    def __setitem__(self, key, value):  #没有返回值
        print(key,value,1111)

    def __delitem__(self, key):   #没有返回值
        print(key)

    def __add__(self, other):
        print(other)
        return self.a1 + other.a2

    def __enter__(self):
        print(111)
        return 999

    def __exit__(self, exc_type, exc_val, exc_tb):
        return 222
#1 类名()  自动执行__init__
# obj = Foo(1,2)
#2 对象()  自动执行__call__
# obj = Foo(1,2)
# ret = obj(1,2,3,4,k1="123")  #111 (1, 2, 3, 4) {'k1': '123'}
# print(ret)                    #123
#3 对象["xx"] 自动执行__getitem__
# obj = Foo(1,2)
# ret = obj["aa"] #aa
# print(ret) #11
#4 对象["xx"]=xx  自动执行__setitem__
# obj = Foo(1,2)
# obj["k1"] = "v1"  #k1 v1 1111
#5 del 对象["xx"] 自动执行__delitem__
# obj = Foo(1,2)
# del obj["k1"] #k1
#6 对象+对象 自动执行__add__
# obj1 = Foo(1,2)
# obj2 = Foo(88,99)
# ret = obj1+obj2  #<__main__.Foo object at 0x0000020F3B08E400>
# print(ret)  #100
#7 with 对象  自动执行__enter__/__exit__
# obj = Foo(1,2)
# with obj as f:
#     print(f)
# # 111
# # 999
# 8 真正的构造方法
class Foo(object):
    def __init__(self, a1, a2):     # 初始化方法
        """
        为空对象进行数据初始化
        :param a1:
        :param a2:
        """
        self.a1 = a1
        self.a2 = a2

    def __new__(cls, *args, **kwargs): # 构造方法
        """
        创建一个空对象
        :param args:
        :param kwargs:
        :return:
        """
        return object.__new__(cls) # Python内部创建一个当前类的对象(初创时内部是空的.).

obj1 = Foo(1,2) 
print(obj1)     #<__main__.Foo object at 0x0000024D96198DD8>

obj2 = Foo(11,12)
print(obj2)     #<__main__.Foo object at 0x0000024D96198DA0>