装饰器3-嵌套装饰器、装饰器类

函数中嵌套装饰器

from functools import wraps
 
def logit(logfile='out.log'):
    def logging_decorator(func):
        @wraps(func)
        def wrapped_function(*args, **kwargs):
            log_string = func.__name__ + " was called"
            print(log_string)
            # 打开logfile，并写入内容
            with open(logfile, 'a') as opened_file:
                # 现在将日志打到指定的logfile
                opened_file.write(log_string + '\n')
            return func(*args, **kwargs)
        return wrapped_function
    return logging_decorator
 
@logit()
def myfunc1():
    pass
 
myfunc1()
# Output: myfunc1 was called
# 现在一个叫做 out.log 的文件出现了，里面的内容就是上面的字符串
 
@logit(logfile='func2.log')
def myfunc2():
    pass
 
myfunc2()
# Output: myfunc2 was called
# 现在一个叫做 func2.log 的文件出现了，里面的内容就是上面的字符串

装饰器类

打日志到文件

from functools import wraps

class logit(object):
    def __init__(self, logfile='out.log'):
        self.logfile = logfile
    
    def __call__(self, func):
        @wraps(func)
        def wrapped_function(*args, **kwargs):
            log_string = func.__name__ + " was called"
            print(log_string)
            with open(self.logfile, 'a') as opened_file:
                opened_file.write(log_string + '\n')
            self.notify()
            return func(*args, **kwargs)
        return wrapped_function
    
    def notify(self):
        pass
    
@logit()
def myfunc1():
    pass

打日志到文件，同时，把引起注意的问题发到一个email
给logit创建子类，添加email的功能

from functools import wraps

class logit(object):
    def __init__(self, logfile='out.log'):
        self.logfile = logfile
    
    def __call__(self, func):
        @wraps(func)
        def wrapped_function(*args, **kwargs):
            log_string = func.__name__ + " was called"
            print(log_string)
            with open(self.logfile, 'a') as opened_file:
                opened_file.write(log_string + '\n')
            self.notify()
            return func(*args, **kwargs)
        return wrapped_function
    
    def notify(self):
        pass
    
@logit()
def myfunc1():
    pass

# 继承
class email_logit(logit):
    def __init__(self, email='admin@myproject.com', *args, **kwargs):
        self.email = email
        super(email_logit, self).__init__(*args, **kwargs)
    
    def notify(self):
        pass

@email_logit()
def myfunc2():
    pass

@email_logit与@logit相比，除了打日志，还会多发一份邮件。