find and remove files with space using find command on Linux

I'd do it this way:

find . -iname 'thumbs.db' -exec rm -rfv {} +

This way, it still works even if your directories contain whitespace in their names.

just to throw this out there

find . -name "*.pyc" -delete

I'm not sure why you're using while.

find . -iname 'thumbs.db' -exec rm -rfv {} \;

...should suffice (and only delete the files you want to, not any BDB files that may be laying around).