https://medium.com/@paulcolomiets/the-future-of-asynchronous-io-in-python-ce200536d847

http://www.jeffknupp.com/blog/2013/06/30/pythons-hardest-problem-revisited/

http://www.jeffknupp.com/blog/2013/04/07/improve-your-python-yield-and-generators-explained/

Python.URLs