import time, functools
def log(text=''):
    def metric(fn):
        @functools.wraps(fn)       #将fn的名字copy给wrappr
        def wrapper(*args, **kw):  #可变参数
            print('%s begin call %s' % (text, fn.__name__))
            t = time.time()
            c = fn(*args, **kw)   #调用fn, 计算，结果传给c
            t1 = time.time()
            print('%s executed in %.2f ms' % (fn.__name__, (t1-t)))
            print('%s end call %s' % (text, fn.__name__))
            return c
        return wrapper
    return metric

@log('AAAAAAA')
def fast(x, y):
    time.sleep(0.0012)
    return x + y;
print(fast(1,2))

@log()

def slow(x, y, z):
    time.sleep(0.1234)
    return x*y*z
print(slow(2,3,5))