futures

# 使用方法一：
def display(*args):
    print(strftime('[%H:%M:%S]'), end=' ')
    print(*args)


def loiter(n):
    msg = '{}loiter({}): doing nothing for {}s...'
    display(msg.format('\t' * n, n, n))
    sleep(n)
    msg = '{}loiter({}): done'
    display(msg.format('\t' * n, n))
    return n * 10


def main():
    print('Script starting')
    with futures.ThreadPoolExecutor(max_workers=3) as executor:  # max_workers=3: 指定线程池中的线程数
        results =  executor.map(loiter, range(5))  # 将 0~4 传递给loiter函数，返回一个迭代器
        display('results:', results)
        for i, result in enumerate(results):  # 取loiter返回的每个结果
            display('result {}:{}'.format(i, result))

main()


# out:
'''
Script starting
[23:10:39] loiter(0): doing nothing for 0s...
[23:10:39] loiter(0): done
[23:10:39] 	loiter(1): doing nothing for 1s...
[23:10:39] 		loiter(2): doing nothing for 2s...
[23:10:39] 			loiter(3): doing nothing for 3s...[23:10:39]
 results: <generator object Executor.map.<locals>.result_iterator at 0x000001BC1D181A10>
[23:10:39] result 0:0
[23:10:40] 	loiter(1): done
[23:10:40] 				loiter(4): doing nothing for 4s...[23:10:40] result 1:10

[23:10:41] 		loiter(2): done
[23:10:41] result 2:20
[23:10:42] 			loiter(3): done
[23:10:42] result 3:30
[23:10:44] 				loiter(4): done
[23:10:44] result 4:40

Process finished with exit code 0

'''