Today I learned about the ASGI specification for Python frameworks:

ASGI (Asynchronous Server Gateway Interface) is a spiritual successor to WSGI, intended to provide a standard interface between async-capable Python web servers, frameworks, and applications.

Python didn’t have asynchronous execution until recently. Since Python 3.4 there’s asyncio in the standard library. asyncio is singl-threaded, single-process - like JavaScript’s event loop.

ASGI is build on top of asyncio.

So, basically, Python now has web servers and frameworks with async capacities. See awesome-asgi for a list of available projects.