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 'OSError: [Errno 12] Cannot allocate memory'. Would you like to know how to fix any of these?

Yes, can you explain how to fix the 'ValueError: can't pickle local object'?

This error usually occurs when you try to pass a local function or an instance of a local class to a process. To fix it, define your function or class at the top level of the module. Would you like more examples?

That makes sense! What about the 'RuntimeError: main thread is not in main loop'?

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 by using if __name__ == '__main__':. Do you need help with anything else?