Asyncio without function colouring

[TobiasHT]

For historical purposes:

How can async support dispatch between sync and async variants of the same code?

Problem A common scenario for library authors is that they accept some callable as a callback for user-defined logic. If the library author wants to add support for async methods, some high-level changes are usually needed, but there’s a problem which ends up percolating down through all sorts of utility functions. Rather than toy examples, I’ll use some of the code I’ve been working on in a branch of the webargs library: def _load_location_data(self, *, schema, req, location): lo…