What are some common errors in Python multiprocessing?

What are some common errors I might encounter when using multiprocessing in Python?

Some common errors include 'ValueError: can't pickle local object', 'RuntimeError: main thread is not in main loop', and issues with shared memory.

Can you explain the 'can't pickle local object' error?

This error occurs when you try to pass a local function or class to a process. To fix it, define the function at the top level of the module.

What about the 'main thread is not in main loop' error?

This error typically happens when you try to start a new process from a thread that is not the main thread. Ensure that your multiprocessing code is executed in the main block.

How can I avoid these errors in my code?

To avoid these errors, always define functions at the top level, use the if __name__ == '__main__': guard, and be cautious with shared resources.