python 装饰器

1、作用域 2、高阶函数 3、闭包

import time

def logger(flag=False):
    def show_time(f):
        def inner(*args,**kwargs):
            start = time.time()
            f(*args,**kwargs)
            end = time.time()
            print(end-start)
            if flag:
                print('record log...')
        return inner
    return show_time


@logger(True)  # foo = show_time(foo)
def foo(a, b):
    print('foo...%d' % (a+b))
    time.sleep(2)


foo(2, 5)