circuitpython/tests/extmod/asyncio_basic.py

try:
    import asyncio
except ImportError:
    print("SKIP")
    raise SystemExit

# CIRCUITPY provides __await()__
async def foo():
    return 42


try:
    foo().__await__
except AttributeError:
    print("SKIP")
    raise SystemExit

import time

if hasattr(time, "ticks_ms"):
    ticks = time.ticks_ms
    ticks_diff = time.ticks_diff
else:
    ticks = lambda: int(time.time() * 1000)
    ticks_diff = lambda t1, t0: t1 - t0


async def delay_print(t, s):
    await asyncio.sleep(t)
    print(s)


async def main():
    print("start")

    await asyncio.sleep(0.001)
    print("after sleep")

    t0 = ticks()
    await delay_print(0.2, "short")
    t1 = ticks()
    await delay_print(0.4, "long")
    t2 = ticks()
    await delay_print(-1, "negative")
    t3 = ticks()

    print(
        "took {} {} {}".format(
            round(ticks_diff(t1, t0), -2),
            round(ticks_diff(t2, t1), -2),
            round(ticks_diff(t3, t2), -2),
        )
    )


asyncio.run(main())