Masking out one list from another

[Yna_Db]

Hello, the answer could be there:

Filter one list using another list

I know this is a variant of some other questions, but I’m new to this, and haven’t figured it out yet. I have list (imported from excel) of sheets I need to create - with sub-lists for sheet number, sheet name, and three custom parameters we need. From that, I can create the sheets by following any of several posted examples. But my script stops as soon as it gets to a sheet that already exists, so I want to filter my list of desired sheets to remove sheets that already exist. Creating the l…