Python 3.4 provisionally introduced an asyncio, providing infrastructure for futures, tasks, protocols, transports and pluggable event loops in the Python Standard Library. Python 3.5 introduced the async and await keywords abstracting away the underlying coroutine mechanism on which asyncio is constructed, providing syntactic sugar for this new style of programming. Python 3.6 provides further language support for asynchronous programming with async comprehensions and async generators. In this session we explore what asyncio is, and demonstrate how to use it to to best effect to solve concurrency problems in Python, including advice on how to best approach testing of asynchronous Python code.