龙叔python-装饰器

装饰器，简单来说就是在优雅的在你执行函数的时候额外帮你去做一些事情，这个事情一般都是通用的，例如打印日志，监察用户权限等操作

其实装饰器原理并不难，所以这里不多讲解，直接举例说明，这里都是简单的说明，装饰器还有很多知识，想要深究可以查查相关知识

简单的装饰器

import time

def count_time(func):
    def wrapper(*args, **kargs):
        print("开始调用函数："+func.__name__)
        print("调用参数为："+str(args))
        start_time = time.time()
        ret = func(*args, **kargs)
        exec_time = time.time() - start_time
        print("调用完了，用时"+str(exec_time))
        return ret
    return wrapper

@count_time(func=11)
def do_somethin(num):
    print("do")
    time.sleep(2)
    print("do ok")
    return num

print(do_somethin)
print(do_somethin(100))

 

带参数的装饰器

import time

def count_time(who):
    def wrapper(func):
        def inner_wrapper(*args, **kargs):
            print("用户"+who+"开始调用函数："+func.__name__)
            print("调用参数为："+str(args))
            start_time = time.time()
            ret = func(*args, **kargs)
            exec_time = time.time() - start_time
            print("调用完了，用时"+str(exec_time))
            return ret
        return inner_wrapper
    return wrapper

@count_time(who="wxl")
def do_somethin(num):
    print("do")
    time.sleep(2)
    print("do ok")
    return num

print(do_somethin)
print(do_somethin(100))

类实现装饰器

import time
class count_time(object):
    def __init__(self,func):
        self.func = func

    def __call__(self,*args, **kargs):
        print("开始调用函数：" + self.func.__name__)
        print("调用参数为：" + str(args))
        start_time = time.time()
        ret = self.func(*args, **kargs)
        exec_time = time.time() - start_time
        print("调用完了，用时" + str(exec_time))
        return ret

@count_time
def do_somethin(num):
    print("do")
    time.sleep(2)
    print("do ok")
    return num

print(do_somethin)
print(do_somethin(100))

类实现装饰器，带参数

import time
class count_time(object):
    def __init__(self,who):
        self.who = who
    def __call__(self,func):
        def wrapper(*args, **kargs):
            print("开始调用函数：" + func.__name__)
            print("调用参数为：" + str(args))
            start_time = time.time()
            ret = func(*args, **kargs)
            exec_time = time.time() - start_time
            print("调用完了，用时" + str(exec_time))
            return ret
        return wrapper

@count_time(who="wxl")
def do_somethin(num):
    print("do")
    time.sleep(2)
    print("do ok")
    return num

print(do_somethin)
print(do_somethin(100))

 

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