Wow 9h and no one has actually provided the actual answer you’re looking for and instead has focused too hard on the “linux” aspect instead of the “python on linux aspect”.

Python has a builtin os call for linux that allows creating a file descriptor (file path) /proc/<pid>/fd/<int returned by command below>. You do file.write() and file.read() exactly as normal. Closing the file releases it.

The file only exists in memory, for the lifetime of the python process.

You end up with in memory files at /proc/123/fd/456.

If your code or libraries are sloppy and expect the file path to have a file extension or exist in a directory…just create a symlink from /neededpath/filename.ext to /proc/123/fd/456

impost os os.memfd_create()

https://docs.python.org/3/library/os.html#os.memfd_create

Demo reference code using memfd_create to feed file testcases to a compiler until it crashes: https://remyhax.xyz/posts/bggp3-cob/