# class Foo: # x=1 # def __init__(self,y): # self.y=y # # def __getattr__(self, item): # print('执行__getattr__') # # f1=Foo(10) # print(f1.y) # print(getattr(f1,'y')) #len(str)--->str.__len__() # f1.sssssssssssssssssssssssssssssssssssss # class Foo: # x=1 # def __init__(self,y): # self.y=y # # def __delattr__(self, item): # print('删除操作__delattr__') # # f1=Foo(10) # del f1.y # del f1.x # # class Foo: # x=1 # def __init__(self,y): # self.y=y # # def __setattr__(self, key, value): # print('__setattr__执行') # # self.key=value # self.__dict__[key]=value # f1=Foo(10) # print(f1.__dict__) # f1.z=2 # print(f1.__dict__) # class Foo: # def __getattr__(self, item): # print('------------->') # # # print(Foo.__dict__) # print(dir(Foo)) # f1=Foo() # # print(f1.x) #只有在属性不存在时，会自动触发__getattr__ # # del f1.x #删除属性时会触发＿ｄｅｌａｔｔｒ＿＿ # # f1.y=10 # f1.x=3 # 设置属性的时候会触发——setattr——— class Foo: def __init__(self,name): self.name=name def __getattr__(self, item): print('你找的属性【%s】不存在' %item) def __setattr__(self, k,v): print('执行setattr',k,v) if type(v) is str: print('开始设置') # self.k=v #触发__setattr__ self.__dict__[k]=v.upper() else: print('必须是字符串类型') def __delattr__(self, item): print('不允许删除属性【%s】' %item) # print('执行delattr',item) # del self.item # self.__dict__.pop(item) f1=Foo('alex') # f1.age=18 #触发__setattr__ # print(f1.__dict__) # print(f1.name) # print(f1.age) # print(f1.gender) # print(f1.slary) print(f1.__dict__) del f1.name print(f1.__dict__)