practice_env.md

https://codeshare.io/

• env to share code and practice. Can be used online by multiple persons in the same time

https://exercism.io/

• code practice and mentorship

http://rosalind.info/about/

• code practice with a twist (focus on bioinformatics, so you will learn also some molecular biology on the way)

https://projecteuler.net/

• math and CS problems to solve

https://codejam.withgoogle.com/codejam/about

https://codejam.withgoogle.com/codejam/past-contests

• algorithmic puzzles

https://pybit.es/

• code challanges

https://www.codingame.com/start

• practice code and play some games in the same time

https://codecombat.com/

• practice code and play some games in the same time

https://checkio.org/

• practice code and play some games in the same time

http://www.cyber-dojo.org/dojo/index/

• code practice, problem solving

https://www.codewars.com/

• code practice, code challenges, problem solving

https://www.hackerrank.com/

• code practice, code challenge, problem solving