版权声明：此文首发于我的个人站带有参数的decorator 装饰器，转载请注明出处。

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// 请给 @performace 增加一个参数，允许传入's'或'ms'：
@performance('ms')
def factorial(n):
    return reduce(lambda x,y: x*y, range(1, n+1))
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import time

def performance(unit):
    def a(f):
        def b(*args, **kw):
            t1 = time.time()
            fn = f(*args, **kw)
            t2 = time.time()
            t = (t2-t1) if unit == 's' else (t2-t1)*1000
            print 'call %s() in %s %s' % (f.__name__, t, unit)
            return fn
        return b
    return a

@performance('ms')
def factorial(n):
    return reduce(lambda x,y: x*y, range(1, n+1))

print factorial(10)
  • time.time() 获取当前时间
  • t = (t2-t1) if unit == ‘s’ else (t2-t1)*1000
    类似 js的三目运算 var t = unit == ‘s’ ? (t2-t1) : (t2-t1)*1000
  • fn.__name__ 获取函数名
  • ‘call %s() in %s %s’ % (f.name, t, unit) %加字母，可对字符串传参