A simple problem, how best to solve it?

[SuchUmami]

This seems quite simple compared to many problems I've had. However, I'm not finding an elegant solution at the moment.

I have two csv files and I'd like to combine them and then write them to another csv file. My problem is that these csv files are constantly being updated and I don't want to miss out on any updates. If I combine a row of data and then save it to another csv file, I might have missed out on further updates to the csv file or I might miss a row of data if several get put into the first csv file at once. However if I simply combine all the rows with the current piece of data, I may have issues saving the new amended data to a csv file. There are various things that can go wrong.

Is there an easy way to do this that I'm not thinking of?

[deanhystad]

Do the files contain a timestamp? Synchronize on that. Otherwise, there is no synchronization and your combined file is meaningless.

[Pedroski55]

these csv files are constantly being updated

If everything is constantly updating, you will just need to do this regularly. You will always miss something!

Set a cronjob to run your Python script every hour or whatever.