Python装饰器重载内置的使用

>>> def traceCall(*args):#跟踪调用
    if trace:
        print('['+','.join(map(str,args))+']')

        
>>> def accessCtrl(forbid):
    def onDecorator(aCls):
        class onInstance:
            def __init__(self,*args,**kargs):
                self.__wrapped=aCls(*args,**kargs)
            def __getattr__(self,attr):
                traceCall('getattr',attr)
                if forbid(attr):
                    raise TypeError('禁止访问:'+attr)
                else:
                    return getattr(self.__wrapped,attr)
            def __setattr__(self,attr,value):
                traceCall('setattr',attr,value)
                # 压缩后的变量名为 _onInstance__wrapped
                if attr=='_onInstance__wrapped':
                    self.__dict__[attr]=value
                elif forbid(attr):
                    raise TypeError('禁止设置:'+attr)
                else:
                    setattr(self.__wrapped,attr,value)
        return onInstance
    return onDecorator

>>> def privateAttr(*privates):
    return accessCtrl(forbid=(lambda attr:attr in privates))

>>> @privateAttr('phone')
class Staff_Private:
    def __init__(self,name,phone):
        self.name=name
        self.phone=phone
    def __str__(self):
        return 'Staff_Private->手机号:'+str(self.phone)
    def __add__(self,num):
        self.phone+=num

#python2.x执行
>>> trace=True
>>> sp1=Staff_Private('梯阅线条',110)
[setattr,_onInstance__wrapped,Staff_Private->手机号:110]
#py2传统类 拦截内置操作表达式调用-隐式调用，print()
>>> print(sp1)
[getattr,__str__]
Staff_Private->手机号:110
#py2传统类 拦截内置操作表达式调用-隐式调用，+
>>> sp1+1
[getattr,__coerce__]
[getattr,__add__]
>>> print(sp1)
[getattr,__str__]
Staff_Private->手机号:111

#python3.x执行
>>> trace=True
>>> sp1=Staff_Private('梯阅线条',110)
[setattr,_onInstance__wrapped,Staff_Private->手机号:110]
#py3没有拦截内置操作 print
>>> print(sp1)
<__main__.accessCtrl.<locals>.onDecorator.<locals>.onInstance object at 0x0000019736C2F4F0>
#py3没有拦截内置操作 + 
>>> sp1+1
Traceback (most recent call last):
  File "<pyshell#11>", line 1, in <module>
    sp1+1
TypeError: unsupported operand type(s) for +: 'onInstance' and 'int'

>>> def traceCall(*args):#跟踪调用
    if trace:
        print('['+','.join(map(str,args))+']')
>>> def accessCtrl(forbid):
    def onDecorator(aCls):
        class onInstance:
            def __init__(self,*args,**kargs):
                self.__wrapped=aCls(*args,**kargs)
            def __getattr__(self,attr):
                traceCall('getattr',attr)
                if forbid(attr):
                    raise TypeError('禁止访问:'+attr)
                else:
                    return getattr(self.__wrapped,attr)
            def __setattr__(self,attr,value):
                traceCall('setattr',attr,value)
                # 压缩后的变量名为 _onInstance__wrapped
                if attr=='_onInstance__wrapped':
                    self.__dict__[attr]=value
                elif forbid(attr):
                    raise TypeError('禁止设置:'+attr)
                else:
                    setattr(self.__wrapped,attr,value)
            # print()触发__str__()
            def __str__(self):
                traceCall('onInstance,__str__')
                # str()触发__str__()
                return str(self.__wrapped)
            # + 触发 __add__()    
            def __add__(self,other):
                traceCall('onInstance,__add__',other)
                return self.__wrapped+other
        return onInstance
    return onDecorator

>>> def privateAttr(*privates):
    return accessCtrl(forbid=(lambda attr:attr in privates))

>>> @privateAttr('phone')
class Staff_Private:
    def __init__(self,name,phone):
        self.name=name
        self.phone=phone
    def __str__(self):
        traceCall('Staff_Private,__str__')
        return 'Staff_Private->手机号:'+str(self.phone)
    def __add__(self,num):
        traceCall('Staff_Private,__add__',num)
        self.phone+=num

        
>>> trace=True
>>> sp1=Staff_Private('梯阅线条',110)
[Staff_Private,__str__]#traceCall调用print()触发__str__()
[setattr,_onInstance__wrapped,Staff_Private->手机号:110]
# print()触发__str__()
>>> print(sp1)
[onInstance,__str__]
[Staff_Private,__str__]
Staff_Private->手机号:110
# + 触发 __add__()
>>> sp1+1
[onInstance,__add__,1]
[Staff_Private,__add__,1]
>>> print(sp1)
[onInstance,__str__]
[Staff_Private,__str__]
Staff_Private->手机号:111