Python 实现一个计时功能的装饰器

# descrbe.py
import time
import functools
def clock(func):
    """this is outer clock function"""
    @functools.wraps(func)  # --> 4
    def clocked(*args, **kwargs):  # -- 1
        """this is inner clocked function"""
        start_time = time.time()
        result = func(*args, **kwargs)  # --> 2
        time_cost = time.time() - start_time
        print(func.__name__ + " func time_cost -> {}".format(time_cost))
        return result
    return clocked  # --> 3
@functools.lru_cache()  # --> 5
@clock  # --> 6
def fib(n):
    """this is fibonacci function"""
    return n if n < 2 else fib(n - 1) + fib(n - 2)
if __name__ == "__main__":
    # 如果有 @functools.wraps(func)  # --> 4 大多数情况下我们希望的输出是这样的
    fib(1) # 输出 fib func time_cost -> 9.5367431640625e-07
    print(fib.__name__)  # 输出 fib
    print(fib.__doc__)  # 输出 this is fibonacci function
    
    # 如果没有@functools.wraps(func)  # --> 4
    fib(1) # 输出 fib func time_cost -> 9.5367431640625e-07
    print(fib.__name__)  # 输出 clocked
    print(fib.__doc__)  # 输出 this is inner clocked function

@clock  # --> 6
def fib(n):
    """this is fibonacci function"""
    return n if n < 2 else fib(n - 1) + fib(n - 2)

fib = clock(fib) 

In [1]: import describe                                                                                                                  
In [2]: describe.fib.__name__        
Out[2]: 'clocked'