[zo1]

It's not clock skew of the CPU/Python in any sense. My theory: Their script is run every 10seconds without taking into account the execution time of previous runs, and they noticed duplicates as the same message would be picked up on multiple executions of their polling script because of probably network delays on the REST API they're querying. So they used the lru_cache decorator to filter out duplicates according to the message content and the user that made it. Really bad design if you ask me, as it's essentially "throwing spaghetti" onto the wall instead of figuring out what's really going wrong. As other people have mentioned, they should instead be using a plain ID to filter out duplicates because it is the most unique identifier.