An attempt at comingling async-code and nonasync-code-in-a-thread in an argonomic way.

Latest release 20241214: Initial release with @agen and @afunc decorators.

One of the difficulties in adapting non-async code for use in an async world is that anything asynchronous needs to be turtles all the way down: a single blocking sychornous call anywhere in the call stack blocks the async event loop.

This module presently provides a pair of decorators for asynchronous generators andfunctions which dispatches them in a Thread and presents an async wrapper.

afunc(*da, **dkw)

A decorator for a synchronous function which turns it into an asynchronous function.

The parameters are the same as for @agen, as this wraps the function in an asynchronous generator which just yields the function result.

Exceptions in the generator are reraised in the synchronous generator.

Example:

@afunc
def func(count):
    time.sleep(count)
    return count

slept = await func(5)

agen(*da, **dkw)

A decorator for a synchronous generator which turns it into an asynchronous generator.

Parameters:

• maxsize: the size of the Queue used for communication, default 1; this governs how greedy the generator may be
• poll_delay: the async delay between polls of the Queue after it was found to be empty twice in succession, default 0.25s
• fast_poll_delay: the async delay between polls of the Queue after it was found to be empty the first time after the start or after an item was obtained

Exceptions in the generator are reraised in the synchronous generator.

Example:

@agen
def gen(count):
    for i in range(count):
        yield i
        time.sleep(1.0)

async for item in gen(5):
    print(item)

Release Log

Release 20241214: Initial release with @agen and @afunc decorators.