This is a potential duplicate of: Google Drive API: list files with no parent (but I hope to restate it clearer).
How can I best use the Google Drive API to list files without parents? i.e. where parents = [].
According to https://developers.google.com/drive/web/search-parameters the only operator allowed on "parents" is "in", while I'm looking to query where len(parents) = 0.
I already have a brute force approach where I then manually compare the parents field to see if it's zero-length, but it's quite slow.