解决Python多线程报错：AttributeError: Can't pickle local object

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发布时间：2026-10-13 | 4人浏览过

原创

本文分析Python多线程编程中常见的AttributeError: Can't pickle local object错误。该错误通常由在类属性中初始化不可序列化的对象（如HTTPDigestAuth）引起。通过修改代码，将认证逻辑移至方法内部而非实例属性，可有效解决序列化失败问题，确保多线程池正常运行。

Python多线程序列化错误排查

报错信息如下所示：

Traceback (most recent call last): File “D:/flaskProject/test.py”, line 35, in test pool.apply(self.out, args=(i,)) File “Python37-32\lib\multiprocessing\pool.py", line 261, in apply return self.apply_async(func, args, kwds).get() File "\lib\multiprocessing\pool.py”, line 657, in get raise self._value File “\Python37-32\lib\multiprocessing\pool.py", line 431, in _handle_tasks put(task) File "\Python37-32\lib\multiprocessing\connection.py”, line 206, in send self._send_bytes(_ForkingPickler.dumps(obj)) File “*\Python37-32\lib\multiprocessing\reduction.py”, line 51, in dumps cls(buf, protocol).dump(obj) TypeError: can't pickle _thread._local objects

原始类的构造函数代码如下：


class threadtest:

def __init__(self, ipList, user, password):
 self.ipList = ipList
 self.httpAuth = HTTPDigestAuth(user, password)
 return

def out(self, i):
 url = "http://" + i + "/name"
 response = requests.get(url, self.httpAuth)
 print(response.text)
 return

def test(self):
 pool = Pool(processes=2)
 for i in self.ipList:
 pool.apply(self.out, args=(i,))
 pool.close()
 pool.join()
 return


if name == ‘main':
ipList = [‘192.168.2.1', ‘192.168.2.2', ‘192.168.2.3', ‘192.168.2.4', ‘192.168.2.5', ]
a = threadtest(ipList, ‘admin', ‘admin')
a.test()

错误原因与修复方案

问题原因分析：

在类的初始化过程中，使用了其他类返回的句柄对属性进行初始化，导致该属性无法被序列化。具体而言，HTTPDigestAuth的返回值不具备可序列化特性，因此无法作为cls(buf, protocol).dump(obj)的参数进行序列化操作。

将原代码中的self.httpAuth = HTTPDigestAuth(httpUser, httpPassword)修改为以下形式：

self.httpUser self.httpPassword

同时，需要将函数HTTPDigestAuth的调用移至类的方法内部执行。

修改后的代码如下：


class threadtest:

def __init__(self, ipList, user, password):
 self.ipList = ipList
 self.user = user
 self.password = password
 return

def out(self, i):
 url = "http://" + i + "/name"
 response = requests.get(url, HTTPDigestAuth(self.user, self.password))
 print(response.text)
 return

def test(self):
 pool = Pool(processes=2)
 for i in self.ipList:
 pool.apply(self.out, args=(i,))
 pool.close()
 pool.join()
 return


if name == ‘main':
ipList = [‘192.168.2.1', ‘192.168.2.2', ‘192.168.2.3', ‘192.168.2.4', ‘192.168.2.5', ]
a = threadtest(ipList, ‘admin', ‘admin')
a.test()

以上为解决Python多线程中AttributeError: Can't pickle local object错误的完整方案，希望对大家有所帮助。