Support multi-level member imports in fixes

[charliermarsh]

ruff  *.py --select TRIO115 --no-cache --fix --unsafe-fixes --preview --isolated

file content:

from trio import Event, sleep
class _RouteMethod(Enum):
    def __init__(self, token: str):
        self._headers = {
        }
    async def request(
    ):
            try:
                        if bool(resp.headers.get("X-RateLimit-Global")):
                            logger.warning(
                        )
                        await sleep(reset_after)
            except OSError as err:
                    await sleep(5)

error

/home/rafal/test/tmp_folder/F_NAME_9541977883458822252.py:12:31: TRIO115 Use `trio.lowlevel.checkpoint()` instead of `trio.sleep(0)`
Found 1 error.
[*] 1 fixable with the --fix option.

error: Fix introduced a syntax error in `/home/rafal/test/tmp_folder/F_NAME_9541977883458822252.py` with rule codes TRIO115: invalid syntax. Got unexpected token '.' at byte offset 39
---
from trio import Event, sleep, lowlevel.checkpoint
class _RouteMethod(Enum):
    def __init__(self, token: str):
        self._headers = {
        }
    async def request(
    ):
            try:
                        if bool(resp.headers.get("X-RateLimit-Global")):
                            logger.warning(
                        )
                        await lowlevel.checkpoint
            except OSError as err:
                    await sleep(5)
---

python_compressed.zip

Originally posted by @qarmin in #8402 (comment)

[dhruvmanila]

@charliermarsh Have you looked at this? Otherwise I can give it a look, seems like an easy fix :)

[charliermarsh]

@dhruvmanila - No, feel free! I don't know how hard or easy it is -- it likely requires some kind of iteration within the Importer.

[dhruvmanila]

Hmm, not sure where does this import come from: from trio import Event, sleep, lowlevel.checkpoint as for me it's always from trio import Event, sleep, lowlevel.

[dhruvmanila]

Oh, the import was a bug in v0.1.5 which was fixed in v0.1.6.

[charliermarsh]

I fixed this specific case, but it doesn't always do the optimal thing.

[charliermarsh]

For example, if the user has import trio.lowlevel, I don't think we leverage the fact that we can do trio.lowlevel.checkpoint.