TestDriven.io

Testdriven.io was founded as a Kickstarter in 2010 and is now one of the most popular Python courses on the market. The founders were inspired by realpython.com to start their own teaching platform for web developers, which they've called testdriven.io. "I don't think there is a single piece of advice, but definitely keep coding," says Test driven's co-founder Fletcher Mertz.