day 23

1.isinstance/issubclass

class Bar:
    pass

class Foo(Bar):
    pass

print(issubclass(Foo,Bar))
obj=Foo()

print(isinstance(obj,Foo))
# print(isinstance([1,2,3],list))

# print(type(obj) is Foo)
# print(type([1,2,3]) is list)

2.反射:通过字符串来反射/映射到对象/类的属性上

class People:
    def __init__(self,name1,age):
        self.name2=name1
        self.age=age

    def run(self):
        print('%s is running' %self.name2)


obj=People('egon',18)

print(hasattr(obj,'name2')) # 'name' in obj.__dict__
# print(getattr(obj,'name')) # obj.__dict__['name']
# print(getattr(obj,'xxx',None)) # obj.__dict__['xxx']

# setattr(obj,'name','EGON') #obj.__dict__['name']='EGON'
# setattr(obj,'xxx',1111) #obj.__dict__['xxx']=111
# print(obj.name)
# print(obj.__dict__)

# delattr(obj,'name')
# print(obj.__dict__)

# import os
# os.remove
# print(hasattr(os,'remove'))
#
# class Ftp:
#     def get(self):
#         print('get')
#
#     def put(self):
#         print('put')
#
#     def login(self):
#         print('login')
#
#     def run(self):
#         while True:
#             cmd=input('>>>: ').strip() #cmd='get'
#             if hasattr(self,cmd):
#                 method=getattr(self,cmd)
#                 method()
#             else:
#                 print('输入的方法不存在')
#
#
# obj=Ftp()
# obj.run()

# __str__: 在对象被打印时自动触发,可以用来定义对象被打印时的输出信息
# 注意:必须返回一个字符串类型的值,


# class People:
#     def __init__(self, name, age):
#         self.name = name
#         self.age = age
#
#     def __str__(self):
#         # print('run..........')
#         return '<name:%s age:%s>' % (self.name, self.age)


# obj1 = People('egon', 18)
# print(obj1)  # print(obj1.__str__())

# obj2=list([1,2,3])
# print(obj2)


# __del__: 在对象被删除时先自动触发该方法,可以用来回收对象以外其他相关资源,比如系统资源
# class Foo:
#     def __init__(self,x,filepath,encoding='utf-8'):
#         self.x=x
#         self.f=open(filepath,'rt',encoding=encoding)
#
#     def __del__(self):
#         print('run.....')
#         # 回收对象关联的其他资源
#         self.f.close()
#
# obj=Foo(1,'a.txt')
# # del obj
# print('主===========>')

# __call__: 在对象被调用时会自动触发该方法,可以用来???
class Foo:
    def __init__(self,x,y):
        self.x=x
        self.y=y

    def __call__(self, *args, **kwargs):
        print(self,args,kwargs)

obj=Foo(1,2)
obj(1,2,a=3,b=4) #obj.__call__(obj,1,2,a=3,b=4)