Shared memory between python processes
From Python 3.8 and onwards you can use multiprocessing.shared_memory.SharedMemory
Not unreasonable.
IPC can be done with a memory mapped file. Python has functionality built in:
http://docs.python.org/library/mmap.html
Just mmap the file in both processes and hey-presto you have a shared file. Of course you'll have to poll it in both processes to see what changes. And you'll have to co-operate writes between both. And decide what format you want to put your data in. But it's a common solution to your problem.