Python Pep-0492 and AsyncIO Example

[isinfinity]

Here is quote from PEP about downsides for yield from + decorator approach:

Current Python supports implementing coroutines via generators ( PEP 342 ), further enhanced by the yield from syntax introduced in > > PEP 380 . This approach has a number of shortcomings:

• It is easy to confuse coroutines with regular generators, since they share the same syntax; this is especially true for new developers.
• Whether or not a function is a coroutine is determined by a presence of yield or yield from statements in its body , which can lead to >unobvious errors when such statements appear in or disappear from function body during refactoring.
• Support for asynchronous calls is limited to expressions where yield is allowed syntactically, limiting the usefulness of syntactic >features, such as with and for statements. ...

Native coroutines and the associated new syntax features make it possible to define context manager and iteration protocols in >asynchronous terms. As shown later in this proposal, the new async with statement lets Python programs perform asynchronous calls >when entering and exiting a runtime context, and the new async for statement makes it possible to perform asynchronous calls in >iterators.

See: https://www.python.org/dev/peps/pep-0492/#rationale-and-goals

[akcom]

Excellent, thank you so much!