Oh wow, thanks for that! I had to alter my real world input data format a bit to make this work, but it chews through 183 datasets in 103 seconds.

My file names don't all start with numbers, and are composed of a few different naming formats, including a few with pesky spaces in the name. So I just gave them arbitrary numbers from 1-183, and that solved my issues.

Now the fun begins of doing all the follow on work to find the unique attributes!