Python3搭配Librabbitmq2.0.0出现TypeError:无法pickle memoryview对象

Hey there, I’ve run into similar Python 3 compatibility hiccups with older librabbitmq versions before, so let’s break down how to fix this pickle error you’re seeing.

Why This Happens #

Librabbitmq 2.0.0’s master branch (as of your installation) has some leftover Python 2-era code that uses memoryview objects in places where Python 3’s pickle module can’t serialize them. Python 3 changed how pickle handles memoryviews, which leads to this exact error when the library tries to pass these objects through serialization—super common in Celery workflows, for example.

Step-by-Step Solutions #

1. Check for a Pre-Existing Fix in the Repository

First, let’s see if the maintainers have already patched this issue:

• Navigate to your cloned librabbitmq directory and fetch the latest updates:

  git fetch origin
  

• Search the repo’s issues or pull requests for mentions of "pickle memoryview". If there’s a dedicated fix branch (like fix-python3-pickle or similar), check it out and reinstall:

  git checkout <name-of-fix-branch>
  make clean
  make install
  

2. Manually Patch the Code (If No Official Fix Exists)

If there’s no pre-made fix, you can tweak the relevant code to convert memoryview objects to bytes before serialization:

• Use the error’s stack trace to find which source file is causing the issue (usually something like librabbitmq/amqp.py).
• Look for lines that create or pass memoryview objects, like this:

  payload = memoryview(message_body)
  

• Replace it with a bytes conversion to make pickle happy:

  payload = bytes(message_body)
  

• Save the file, then reinstall the library to apply the change:

  make clean
  make install
  

3. Switch to a More Python 3-Compatible Version

If the 2.0.0 master branch is too buggy, consider moving to a later tag or release that explicitly supports Python 3:

• List all available tags in the repo:

  git tag -l
  

• Check out a tag like 2.0.1 (if it exists and fixes Python 3 issues):

  git checkout 2.0.1
  make clean
  make install
  

• Alternatively, if a fixed version is on PyPI, install it directly with pip:

  pip install librabbitmq>=2.0.1
  

4. Temporary Workaround: Switch Serialization Backend (For Celery Users)

If you’re using librabbitmq with Celery, you can avoid the pickle issue entirely by using a different serializer like JSON:

• Update your Celery configuration to use json instead of pickle:

  app = Celery('myapp')
  app.conf.update(
      task_serializer='json',
      accept_content=['json'],
      result_serializer='json',
  )
  

Note: This is a quick workaround—you’ll still want to fix the librabbitmq issue if you need pickle support for complex objects.

内容的提问来源于stack exchange，提问作者dowjones123