import?time
def?performance(unit):
????t1=time.time()????
????def?decorator(f):????????????????
????????def?fn(*args,?**kw):????????????
????????????r=f(*args,**kw)????????????
????????????t2=time.time()????????????
????????????print?'call?%s()?in?%d?%s'?%f.__name__,t2-t1,unit????????????
????????????return?r????????
????????return?fn????
????return?decorator??
??????????
????@performance('ms')
????def?factorial(n):????
????????return?reduce(lambda?x,y:?x*y,?range(1,?n+1))
????print?factorial(10)

Traceback?(most?recent?call?last):
??File?"index.py",?line?20,?in?
????print?factorial(10)
??File?"index.py",?line?10,?in?fn
????print?'call?%s()?in?%d?%s'?%f.__name__,t2-t1,unit
TypeError:?not?enough?arguments?for?format?string

另外裝飾器里為什么一定要插r=f(*args,**kw)這句？而且我不用無參數標識符，用r=f(n)這樣的就不行么？