I think there genuinely is a bit of a hurdle (and is yet another reason we should be teaching programming in all undergraduate science courses).
Personally, I think the best way it to attend an in-person course, such as one of the Software Carpentry courses (e.g. https://swcarpentry.github.io/python-novice-inflammation/) and their future workshops can be found: https://software-carpentry.org/workshops/.
A bit of a self-plug. I actually teach a one-day intro to python course for the Royal Society of Biology (next one: https://www.rsb.org.uk/events?event=programmingforbiologists) and my colleague and I have put some effort into creating YouTube videos that should allow learners to do the course in their own time soon (see http://chasnelson.co.uk/python/).
For the future, I was also involved in a Royal Microscopical Society-supported week-long course on Python for Bioimage Analysis and all those resources are available on GitHub (https://github.com/IAFIG-RMS/Python-for-Bioimage-Analysis). Some of the topics have been uploaded as video lectures and it is our plan to do that for the other topics as soon as we can.
We plan to run this course again in the future but dates are still to be decided.
Finally, a personal thought, many ‘programming for biologists’ courses can be great. However, they are often focused at bioinformatics and not image analysis - these two fields use a lot of different concepts so finding a course focused on imaging (or on neither for beginners) can be the difference between useful and useless training.