e-dard/flask-s3 — pull request #31 by andrewsnowden (2014-10-23 09:48:36+00:00)
Title: Cache busting

Option that appends file hashes as query strings to static URLs. This forces a refetch if the content changes even if the expiry header has been set far into the future.

Webassets does this for scripts and stylesheets (http://webassets.readthedocs.org/en/latest/expiring.html) but there isn't anything that does it for images.