import  time
def logger(flag):
    def show_time(f):        #装饰器函数
        def inner(*x,**y):         #闭包函数
            stat = time.time()
            f(*x,**y)
            end = time.time()
            print('spend %s' % (end - stat))
            if flag == 'true':
                print('日志记录')
        return inner
    return show_time

@logger('true') #show_time
#@show_time  #foo = show_time(foo)
def foo(*a,**b):
    sums = 0
    for i in a:
        sums += i
    print(sums)
    time.sleep(1)
foo(1,2,3,4)