import time

import functools

def clock(func):

    @functools.wraps(func)#还原被装饰函数的__name__和__doc__属性

    def clocked(*args,**kwargs):#支持关键字参数

        t0 = time.perf_counter()

        result = func(*args,**kwargs)

        elapsed = time.perf_counter()- t0

        name = func.__name__

        arg_lst = []

        if args:

            arg_lst.append(','.join(repr(arg) for arg in args))

        if kwargs:

            pairs = ['%s = %r' % (k,w) for k,w in sorted(kwargs.items())]

            arg_lst.append(','.join(pairs))

        arg_str = ','.join(arg_lst)

        print('[%0.8fs]%s(%s) -> %r' % (elapsed,name,arg_str,result))

        return result

    return clocked

@functools.lru_cache(maxsize=128,typed = False) #把耗时的函数结果保存起来，避免传入相同的参数重新计算,typed=true，把浮点数和整数分开保存

@clock

def fibonacci(n):

    if n <2:

        return n

    return fibonacci(n-2) + fibonacci(n-1)

if __name__ == '__main__':

    print(fibonacci(30))