Telethon报错ValueError: readexactly size不能小于零如何解决？

问题描述 #

我遇到了如下报错，推测可能和频繁请求有关，但加了异常捕获代码还是没用。试过在代码不同位置用多种方式捕获异常，都没效果，查了论坛和库文档也没找到解决方案。

报错信息 #

Unexpected exception in the receive loop
Traceback (most recent call last):
  File "C:\Users\fazuq\AppData\Local\Programs\Python\Python39\lib\site-packages\telethon\network\connection\connection.py", line 324, in _recv_loop
    data = await self._recv()
  File "C:\Users\fazuq\AppData\Local\Programs\Python\Python39\lib\site-packages\telethon\network\connection\connection.py", line 367, in _recv
    return await self._codec.read_packet(self._reader)
  File "C:\Users\fazuq\AppData\Local\Programs\Python\Python39\lib\site-packages\telethon\network\connection\tcpfull.py", line 27, in read_packet
    body = await reader.readexactly(packet_len - 8)
  File "C:\Users\fazuq\AppData\Local\Programs\Python\Python39\lib\asyncio\streams.py", line 709, in readexactly
    raise ValueError('readexactly size can not be less than zero')
ValueError: readexactly size can not be less than zero

我的代码 #

async def get_voice_messages(client: TelegramClient, dialog_id: int):
    try:
        messages: list = await client.get_messages(dialog_id, None, filter = InputMessagesFilterVoice)
    except ValueError:
        print('я тута')
        return
    except:
        print('или тута')
        return
    print('See dialog: {}'.format(dialog_id))
    for message in messages:
        try:
            if message.out:
                # await client.delete_messages(message.peer_id.user_id, message_ids=[message.id])
                print('Success delete message: {} from peer: {}'.format(message.id, message.peer_id.user_id))
        except:
            print('No have voice messages!')


async def get_dialog_list() -> None:
    loop = asyncio.get_event_loop()
    async with TelegramClient(config['session_name'], config['api_id'], config['api_hash'], loop = loop) as client:
        try:
            dialogs: list = await client.get_dialogs(ignore_migrated = True)
        except ValueError:
            return

        tasks: list = []
        for dialog in dialogs:
            try:
                if not dialog.is_channel and not dialog.is_group and not dialog.entity.bot:
                    tasks.append(asyncio.create_task(get_voice_messages(client, dialog.id)))
            except ValueError:
                continue
        start_tasks: tuple = await asyncio.gather(*tasks)
        print('Success delete all messages!')

def start_thread() -> None:
    asyncio.run(get_dialog_list())

解决方法 #

• 限制并发请求数量：当前代码一次性创建所有对话的请求任务，并发过高容易触发Telegram限制或连接异常。用asyncio.Semaphore控制并发数，比如设为5：

  # 修改get_dialog_list函数
  async def get_dialog_list() -> None:
      loop = asyncio.get_event_loop()
      semaphore = asyncio.Semaphore(5)  # 限制同时5个请求
      async with TelegramClient(config['session_name'], config['api_id'], config['api_hash'], loop = loop) as client:
          try:
              dialogs: list = await client.get_dialogs(ignore_migrated = True)
          except ValueError:
              return
  
          tasks: list = []
          for dialog in dialogs:
              try:
                  if not dialog.is_channel and not dialog.is_group and not dialog.entity.bot:
                      tasks.append(asyncio.create_task(get_voice_messages(client, dialog.id, semaphore)))
              except ValueError:
                  continue
          start_tasks: tuple = await asyncio.gather(*tasks)
          print('Success delete all messages!')
  
  # 修改get_voice_messages函数
  async def get_voice_messages(client: TelegramClient, dialog_id: int, semaphore):
      async with semaphore:
          try:
              messages: list = await client.get_messages(dialog_id, None, filter = InputMessagesFilterVoice)
          except ValueError:
              print('я тута')
              return
          except:
              print('или тута')
              return
          print('See dialog: {}'.format(dialog_id))
          for message in messages:
              try:
                  if message.out:
                      # await client.delete_messages(message.peer_id.user_id, message_ids=[message.id])
                      print('Success delete message: {} from peer: {}'.format(message.id, message.peer_id.user_id))
              except:
                  print('No have voice messages!')
  

• 更换连接类型：报错来自TCPFull连接的数据包解析，换成TCPAbridged连接可降低这类问题：

  from telethon.network.connection.tcpabridged import TCPAbridged
  
  # 创建客户端时指定连接
  async with TelegramClient(config['session_name'], config['api_id'], config['api_hash'], loop=loop, connection=TCPAbridged) as client:
      # 原有逻辑
  

• 升级Telethon版本：该错误可能是旧版本的bug，执行命令升级：

  pip install --upgrade telethon
  

• 添加请求间隔：遍历对话时加短暂延迟，避免请求过于密集：

  for dialog in dialogs:
      try:
          if not dialog.is_channel and not dialog.is_group and not dialog.entity.bot:
              tasks.append(asyncio.create_task(get_voice_messages(client, dialog.id)))
              await asyncio.sleep(0.5)  # 每次创建任务后延迟0.5秒
      except ValueError:
          continue
  

内容的提问来源于stack exchange，提问作者Way Sanders