"ROWM" (read once, write many) robust file copy program that utilizes checksum sidecar files. (1) Read the data, compute a checksum as a 'source of truth' and store it as $filename.checksum_type, and then (2) write the data (and the computed checksum) to N destinations simultaneously, and (3) Compute the checksum of the file on each destination and compare it against the source of truth

Could use "tee" to limit the reading to just one instance but I would like to try Python.

Hoping to write the core of it as an open-source hobby project to learn Python multithreading and then extend it for the actual problem I need to solve at work through the use of config files.