python functools.lru_cache做备忘功能

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))