This removes leading and trailing whitespace from every line and discards lines left with nothing in them.
Two cleanups in one pass
Trimming fixes values padded with invisible characters. Removing empties clears the gaps that padding and copy-paste leave behind.
Why it belongs first
Almost every other operation behaves better on trimmed input. Comparisons match, filters find what they should, and counts reflect real entries rather than blank rows.
The invisible failure it prevents
A trailing space makes two identical-looking values different to every tool that compares them, with nothing on screen to explain why.
Try it: Trim & Remove Empty Lines on SeoWolf's Notepad.