Duplicating files in Calibre

[ladfm]

I currently have a ton of books in Calibre. Most of them are in AZW3 format. When I import using the script, often it imports duplicate epub files. Does the script look for existing .azw3 files?

[Satsuoni]

Which script? Mine does not do Calibre import, and AFAIK, Jadehawk's does not do epub conversion. But either way neither should check for duplicates, i think?