I’ve tried many different online training options. Datacamp has the best format for learning, in my opinion. What I like is, you are introduced visually to some material to learn, then you have to take that and complete some learning exercises before continuing.

You always have the option to skip to the solution if you are completely stumped, but if you are serious about learning, you will use all resources you can muster to complete the material on your own. The points you earn give you an idea of how you are doing.

-via Linkedin