Python-19-类装饰器

​接上节内容，我们继续介绍类装饰器，顾名思义类装饰器就是类闭包。​

定义一个类装饰器

​需求：实现一个类装饰器，能够在方法执行时打印日志，并且发送通知到指定地方。
​

from functools import wraps

class logAndNotify(object):

    # 初始化，定义日志路径
    def __init__(self,logfile='service.log'):
        self.logfile = logfile
    
    # 使类成为可调用对象
    def __call__(self,func):

        @wraps(func)
        def wrap_func(*args,**kwargs):
            info = func.__name__+'was called'

            # 实现写日志
            with open(self.logfile,'a') as f:
                f.write(info+'\n')
            
            # 实现通知
            self.notify()

            return func(*args,**kwargs)
        return wrap_func
    
    def notify(self):
        print('notify has been send...')

@logAndNotify()
def sayHi(name):
    print('hello',name,'!')

res = sayHi('phyger')
print(res)

执行结果：

➜ RemoteWorking git:(master) ✗ /usr/bin/python3 /root/RemoteWorking/test/test.py
notify has been send...
hello phyger !
None

类装饰器功能扩展

如果我们想要在此类装饰器的基础上，增加发送邮件的功能，就可以利用类的继承特性来实现。

from functools import wraps


class logAndNotify(object):

    # 初始化，定义日志路径
    def __init__(self, logfile="service.log"):
        self.logfile = logfile

    # 使类成为可调用对象
    def __call__(self, func):
        @wraps(func)
        def wrap_func(*args, **kwargs):
            info = func.__name__ + "was called"

            # 实现写日志
            with open(self.logfile, "a") as f:
                f.write(info + "\n")
            # 实现通知
            self.notify()

            return func(*args, **kwargs)

        return wrap_func

    def notify(self):
        print("notify has been send...")


class NewWarp(logAndNotify):

    # 初始化邮件地址
    def __init__(self, email_address='phyger@', *args, **kwargs):
        self.email_address = email_address
        super(NewWarp,self).__init__(*args, **kwargs)

    # 重写notify方法
    def notify(self):
        print("notify has been send...")
        print('email sended...to',self.email_address)
    

@NewWarp()
def sayHi(name):
    print("hello", name, "!")


res = sayHi("phyger")
print(res)

执行结果：

➜ RemoteWorking git:(master) ✗ /usr/bin/python3 /root/RemoteWorking/test/test.py
notify has been send...
email sended...to phyger@
hello phyger !
None