Watching tech talks from language conferences can be pretty enlightening - Python and Golang for example both have a lot of great videos kicking about on YouTube about lesser known or more cutting edge topics. Check out the Pycon 2017 YouTube channel for example: https://www.youtube.com/channel/UCrJhliKNQ8g0qoE_zvL8eVg/vid.... There are lots of channels like this.
For Python, I've found watching Raymond Hettinger's and Dave Beazley's videos especially interesting, even though some of the topics they talk about are pretty esoteric. If you find someone who is better than average at presenting tech talks, you can binge-watched their most popular stuff on YouTube (or only the stuff that is relevant to you).
Pluralsight (https://www.pluralsight.com) is decent for structured video courses - the quality is generally high but content gets outdated fast, and my impression was videos can seem drawn out (I think authors get paid by the minute of video watched). Still worth starting a trial if you haven't done so yet.