Asynchronous programming

Asynchronous programming gained a lot of traction in the last few years. In Python 3.5, it finally got some syntax features that solidify concepts of asynchronous execution. But this does not mean that asynchronous programming is possible only starting from Python's 3.5 version. A lot of libraries and frameworks were provided a lot earlier, and most of them have origins in the old versions of Python 2. There is even a whole alternate implementation of Python called Stackless (see Chapter 1, Current Status of Python) that concentrated on this single programming approach. Some of these solutions, such as Twisted, Tornado, and Eventlet, still have huge and active communities and are really worth knowing. Anyway, starting from Python 3.5, asynchronous programming is easier than ever before. Therefore, it is expected that its built-in asynchronous features...