New Flask, Jinja2, Click, Werkzeug, ItsDangerous, and MarkupSafe major release candidates

written by Philip Jones on 2021-04-29 in Releases

The Pallets team is pleased to announce that release candidates are now available for the next major version of each project.

Check out the changelogs for every project to see what's new:

Please help us prepare for the final release by testing the prerelease versions and reporting any issues you have. To upgrade to pre-releases with pip, use the --pre flag, e.g.:

pip install -U --pre Flask

These new major versions all drop support for Python 2 and 3.5, requiring Python 3.6 as the minimum supported version.

Release highlights

These are a few highlights, see the changelogs linked above for the full release details. More detailed posts about each project's highlights will be made with the final releases.

  • All projects (Jinja coming soon) now provide type hints.
  • Flask gains limited async/await support.
  • Flask supports nested blueprints.
  • Flask tells the browser to cache static files more intelligently, so changes to CSS or images show up immediately.
  • Flask introduces short form route decorators, such as as a shortcut for @app.route(methods=["POST"]).
  • Click's shell completion system has been rewritten.
  • Click will now prompt for values where they are omitted.
  • Werkzeug now provides send_file and send_from_directory helpers.
  • Werkzeug's test client always returns a Response object.
  • Werkzeug's multipart parsing performance increases by a factor of 15.

Release date

The Pallets team is aiming to release on or before PyCon 2021, i.e. a target release date of the 11th of May 2021.