I keep my movie collection in an annex. I recently wrote a python script that pulls information about each movie down from IMDB and stores it as metadata on the annexed file. One of the attributes I'm storing is rating. For instance, the metadata for my copy of Blade Runner looks like this:
$ git annex metadata blade_runner.mkv
metadata blade_runner.mkv
director="Ridley Scott"
director-lastchanged=2016-04-20@04-21-33
genre="Sci-Fi"
genre="Thriller"
genre-lastchanged=2016-04-20@04-21-33
lastchanged=2016-04-20@04-21-33
rating=8.2
rating-lastchanged=2016-04-20@04-21-33
runtime=117
runtime-lastchanged=2016-04-20@04-21-33
title="Blade Runner"
title-lastchanged=2016-04-20@04-21-33
year=1982
year-lastchanged=2016-04-20@04-21-33
ok
I can now use the metadata to ask git annex to show me all movies with a rating of 8.2.
$ git annex find --metadata rating=8.2
blade_runner.mkv
However, that isn't very useful. What I want to do is specify a range. For example, I want to ask git annex to show me all movies with a rating above 8:
$ git annex find --metadata rating=>8
Or, show me all movies with a rating between 6 and 9
$ git annex find --metadata rating=>6 rating=<9
Is something like this possible?
I'd like to do something similar with the year attribute. Right now I can use metadata views to group movies by their release year, which is pretty neat.
$ git annex view "year=*"
But I would also like to be able to give a range so that I could group movies by release decade, for example.

This is a great idea! So great that I got in the ol' time machine, set the dial for February 29th 2016, and convinced past-me to implement it then.
(For some reason, past-me decided to make the syntax
field>=numberandfield<=numberinstead of the syntax you suggested. He can be a bit of a stick in the mud with his own outdated ideas that he holds onto tightly.)Perfect. It works great! Thanks.
Is this documented anywhere? I see it in the release notes now, but I didn't see anything mentioned in the metadata, metadata driven views or metadata design pages, or the git-annex-metadata man page. I'm not sure where I should look to see how else I can query the metadata.
It's documented in git-annex-matching-options and git-annex-preferred-content.
Could you share your IMDB -> metadata script? It would be interesting to see what works in practice.
I was about to write something similar and why duplicate work?
Absolutely!
https://github.com/pigmonkey/metamovie
It's a quick hack job, but has been working so far. I haven't played around with automatically adding metadata yet. The filename based search does the right thing 99% of the time (at least for my file names), but I still always want to confirm that it is using the right movie data, so I'm running the script manually and keeping it interactive.