Unique ID on groups of records

[cireost]

Hi - I am trying to create a unique ID on a group of records. The pattern to the group is separated by empty rows in either Column A or E. Column A always has 5 records but column E is unpredictable. Please see attached input and expected output. Thanks!

[cireost]

This works, thank you!!

Do you have a good guide on how to use Regex that you could link?  

[Thableaus]

@cireost 

This website is very good: https://www.rexegg.com/

Also, I encourage you to read the book "Mastering Regular Expressions".

It explains how the whole engine works and the numerous flavours RegEX has. Alteryx uses Perl "flavour".

Cheers,