如何检查线程（来自一堆线程）是否抛出异常？

Question

我创建了一个运行多个线程的脚本。每个线程在无限循环中运行一个函数。我想知道是否有任何线程抛出异常。

这是线程启动的基本结构：

def main():
    VODP = Packager()
    WINSCP = WinSCP()
    threadList = []
    threadList.append(threading.Thread(target=VODP.scan))
    threadList.append(threading.Thread(target=WINSCP.ftp_sender))
    threadList.append(threading.Thread(target=WINSCP.ftp_status_checker))
    threadList.append(threading.Thread(target=WINSCP.synchronize))
    for thread in threadList:
        thread.start()
    for thread in threadList:
        thread.join()

main()

这是一个具有无限循环功能的类的示例：

class Packager:
    def __init__(self):
        self.rootDir, self.scanTime, self.extendedScanTime = self.configure_packager()
        self.foldersReadyToPack = []
    def scan(self):
        while True:
            if self.foldersReadyToPack == []:
                for dirpath, dirnames, filenames in os.walk(self.rootDir):
                    if(folder_verifier(dirpath)):
                        #print("Currently scanned folder: ", dirpath)
                        package_creator(dirpath)
                if len(self.foldersReadyToPack) > 0:
                    #print(f'Folders with suitable files has been found!')
                    packingQueue = PackingQueue(self.foldersReadyToPack)
                    packingQueue.execute_packing()
                    self.foldersReadyToPack = packingQueue.elements

我怎样才能做到这一点？如何获取线程抛出异常并且不再无限循环执行其任务的信息？当程序中发生可疑情况时，我希望将此类信息传递给负责发送电子邮件的班级。

Answer 1

你可以使用concurrent.futures:

import concurrent.futures


def foo_with_exc(a, b):
    raise ValueError()


def thread_starter():
    with concurrent.futures.ThreadPoolExecutor(max_workers=2) as executor:
        future = executor.submit(foo_with_exc, 1, 2)

        # Raise any exceptions raised by thread
        return future.result()


try:
    thread_starter()
except ValueError as e:
    print("Exception!")