@wraps() 不表现不返回原始函数值

Question

我写了一个相当基本的装饰器：

def test_speed(f, *args, **kwargs):
    """This decorator will print out the time taken for input function to run."""

    @wraps(f)
    def wrapper():
        """Wrapper function returned by the outer function."""
        start = time.time()
        to_return = f(*args, **kwargs)
        end = time.time()
        print(f"The function {__name__} completed in {end-start} seconds.")

        return to_return
    return wrapper

在一个名为工具的项目中的一个名为装饰器的 python 脚本中。我已将此项目添加到我用于练习使用多处理模块的第二个项目的配置中。我写了一些测试函数来检查多处理一些循环的速度：

""" A script to practice using multiprocessing effectively in python."""

from decorators import *
from multiprocessing import *


def _loop(i, process_number):
    for i in range(i):
        if i % 500 == 0:
            print(f'{i} iterations of loop {process_number}.')


def serial_looping():

    _loop(10000, 'one')
    _loop(10000, 'two')
    _loop(10000, 'three')


@test_speed
def parallel_looping():
    loop_one = Process(target=_loop, args=(10000, 'one'))
    loop_two = Process(target=_loop, args=(10000, 'two'))
    loop_three = Process(target=_loop, args=(10000, 'three'))


if __name__ == '__main__':
    serial_looping()
    parallel_looping()

def serial_looping():

    _loop(10000, 'one')
    _loop(10000, 'two')
    _loop(10000, 'three')


@test_speed
def parallel_looping():
    loops = []
    loops.append(Process(target=_loop, args=(10000, 'one')))
    loops.append(Process(target=_loop, args=(10000, 'two')))
    loops.append(Process(target=_loop, args=(10000, 'three')))
    for loop in loops:
        loop.start()
        print('loop')


if __name__ == '__main__':
    serial_looping()
    parallel_looping()

我的问题是，当调用包装函数时，它不是名称，而是说明包装器的项目名称、装饰器，如下所示：

The function decorators completed in 5.841255187988281e-05 seconds.

当然这应该是： The function serial_looping completed in 5.841255187988281e-05 seconds.

Answer 1

您应该在函数 f 上调用 __name__：

print(f"The function {f.__name__} completed in {end-start} seconds.")

原因是__name__，默认指的是封闭函数；我不认为 @wraps 会覆盖这种行为；它不知道您打算打印什么。

@wraps() 不表现不返回原始函数值

@wraps() not behaving isn't returning the original functions values

python-3.x

functools

python-decorators