DataQuest is a recently launched online data science learning platform for python. The site consists of a gamified series of missions that increase in difficulty as your skills progress. Here are a few other features of the site.

• Sample Code
• Live, Interactive Browser-based Coding Environment
• Step by Step Instructions
• Instant Feedback
• Helpful Forums for Q&A

The site is still under development and the founder, Vik Paruchuri, is looking for help developing more content and missions for the site. If that is something of interest to you, get in touch with Vik via the DataQuest website.