在 Python 上出现异常后重新启动线程

Question

我编写此脚本是为了从特定ftp上的数据中提取元数据，然后将其保存在特定目录中，然后随机等待一段时间，然后再次提取等...所以有2点：第一：从特定的ftp中提取第二：保存它并等待随机时间，这取决于所使用的ftp。

有时我有来自ftp的超时问题。当它发生时，不再从线程中提取，保存或等待。其他线程继续工作，直到它们也遇到超时问题。

我试图捕获异常以"重新启动"与ftp超时问题有关的线程。但没有任何改变。

有人可以帮助我找到"重新启动"线程的方法吗？

非常感谢

class ftp_id(Thread):
    def __init__(self, ftpID):
        Thread.__init__(self)
        self.ftpID = ftpID
    def run(self):
        while True:
            with verrou:
                siteID = self.ftpID
                directory = str(datetime.now())[:-16].replace('-', '')
                filename = siteID + '_' + str(datetime.now())[:-7].replace(':', '').replace(' ', '_').replace('-', '') + '.txt'
                dictstr = myExtract(siteID)
                myWriteFile(directory, filename, dictstr)
                pendingtime = myWaiting(siteID, dictstr)
            time.sleep(pendingtime)
        except :
            self.stop = True
            self.stop = False
            self.start()
            self.join()
thread_01 = ftp_id("ftp-01")
thread_02 = ftp_id("ftp-02")
thread_03 = ftp_id("ftp-03")
thread_04 = ftp_id("ftp-04")
thread_01.start()
thread_02.start()
thread_03.start()
thread_04.start()
thread_01.join()
thread_02.join()
thread_03.join()
thread_04.join()

Answer 1

线程

无法重新启动。所以你应该把异常处理放在while块中，永远不要退出循环：

def download(server):
    while True:
        try:
            with verrou:
                now = datetime.now()
                directory = '{:%Y%m%d}'.format(now)
                filename = '{}_{:%Y%m%d_%H%M%S}.txt'.format(server, now)
                dictstr = myExtract(server)
                myWriteFile(directory, filename, dictstr)
                pendingtime = myWaiting(server, dictstr)
            time.sleep(pendingtime)
        except:
            # restart
            pass
threads = [
    Thread(target=download, args=(server,))
    for server in ["ftp-01", "ftp-02", "ftp-03", "ftp-04"
]
for thread in threads:
    thread.start()
for thread in threads:
    thread.join()

Answer 2

线程

无法在python中重新启动...粗略地说，您可以只实现自己的"线程"类，该类不是真正的线程

class ftp_id(object): # this is a bad name for a class please see pep8
    def __init__(self, ftpID):
        super(ftp_id,self)
        self.ftpID = ftpID
        self.thread = None
        self.thread_stop = False
    def __getattr__(self):
        return getattr(self.thread)
    def start(self):
        if self.thread:
           self.thread_stop = True
           self.thread.terminate()
           self.thread.join()
        self.thread = threading.Thread(target = self.run)
        self.thread.start()
    def run(self):
        self.thread_stop = False
        while not self.thread_stop:
            with verrou:
                siteID = self.ftpID
                directory = str(datetime.now())[:-16].replace('-', '')
                filename = siteID + '_' + str(datetime.now())[:-7].replace(':', '').replace(' ', '_').replace('-', '') + '.txt'
                dictstr = myExtract(siteID)
                myWriteFile(directory, filename, dictstr)
                pendingtime = myWaiting(siteID, dictstr)
            time.sleep(pendingtime)

虽然我不知道这是否真的回答了你的问题