Fix typing errors for MicroPython

[makermelissa]

Fixes #220. Tested on Raspberry Pi Pico with latest MicroPython.

[makermelissa]

Ok... weird error.

black....................................................................Failed
- hook id: black
- exit code: 1

Traceback (most recent call last):
  File "/home/runner/.cache/pre-commit/repois0o6nr8/py_env-python3/bin/black", line 8, in <module>
    sys.exit(patched_main())
  File "/home/runner/.cache/pre-commit/repois0o6nr8/py_env-python3/lib/python3.7/site-packages/black/__init__.py", line 6606, in patched_main
    patch_click()
  File "/home/runner/.cache/pre-commit/repois0o6nr8/py_env-python3/lib/python3.7/site-packages/black/__init__.py", line 6595, in patch_click
    from click import _unicodefun  # type: ignore
ImportError: cannot import name '_unicodefun' from 'click' (/home/runner/.cache/pre-commit/repois0o6nr8/py_env-python3/lib/python3.7/site-packages/click/__init__.py)

[dhalbert]

See extensive discussion in #circuitpython-dev. Black and click need to be moved up to the latest versions.

[makermelissa]

Hmm, this may be problematic:

SyntaxError: from __future__ imports must occur at the beginning of the file

This requirement pretty much breaks what the PR fixes.

[makermelissa]

Testing on Raspberry Pi, enclosing from __future__ imports in a try/except block also results in an error. Back to the drawing board on this one.

[dhalbert]

Hmm, this may be problematic:

SyntaxError: from __future__ imports must occur at the beginning of the file

This requirement pretty much breaks what the PR fixes.

Yes, this is why I added from __future__ import annotations to CircuitPython. I guess there could be two versions of what to import.

[dhalbert]

The only reason to include from __future__ import annotations is to support Python 3.6. Perhaps we should stop supporting that. It breaks Jetson; do you know what else it breaks?

[makermelissa]

The only reason to include from __future__ import annotations is to support Python 3.6. Perhaps we should stop supporting that. It breaks Jetson; do you know what else it breaks?

Hmm, let me test without it

[makermelissa]

Ok, everything seems to work without it and I'm ok with not having it since we require 3.7 anyways.

[makermelissa]

Importing Detector for typing purposes was proving to be problematic without the futures line, so I just removed it. Just a normal detector import (without the TYPE_CHECKING line) caused a circular import issue anyways.

[makermelissa]

Sweet, so this was tested on MicroPython, Linux Raspberry Pi, and passed all the the checks.

[dhalbert]

I think the Jetson guides will need to describe how to install Python 3.7 or later for user-only use (not updating the system Python). I would expect this is possible. https://forums.developer.nvidia.com/t/python-3-6-approaching-end-of-life/194961 and other places in the that forum discuss using later versions of Python (some successful, some not).

[makermelissa]

I think the Jetson guides will need to describe how to install Python 3.7 or later for user-only use (not updating the system Python). I would expect this is possible. https://forums.developer.nvidia.com/t/python-3-6-approaching-end-of-life/194961 and other places in the that forum discuss using later versions of Python (some successful, some not).

Ok, I'll take a look tomorrow. This PR mainly is for fixing usage on MicroPython which does not work at all at this point in time.

[tekktrik]

Can you add the from . import XXXXX to the try/except and escape it in quotes, like "Detector"?

[tekktrik]

Ah, never mind, sounds like it was causing problems, never mind.

[makermelissa]

Can you add the from . import XXXXX to the try/except and escape it in quotes, like "Detector"?

It might be possible to use quote on the type name so that an import isn't necessary.

[makermelissa]

I think the Jetson guides will need to describe how to install Python 3.7 or later for user-only use (not updating the system Python). I would expect this is possible. https://forums.developer.nvidia.com/t/python-3-6-approaching-end-of-life/194961 and other places in the that forum discuss using later versions of Python (some successful, some not).

Done. See https://learn.adafruit.com/circuitpython-libraries-on-linux-and-the-nvidia-jetson-nano/initial-setup#install-python-3-dot-7-and-make-default-3114929-19.

[makermelissa]

Is this waiting on something from me?

[tekktrik]

Not sure if @dhalbert had any followup about __futures__, but looking at this now, but you could do the TYPE_CHECKING trick for importing detectior in the try/except I think if you really wanted to keep it. But with argnames like detector I think it's clearly documented either way haha.

[makermelissa]

I think I want to leave it out because it's really touchy when trying to get it working all with MicroPython, CPython, and PyLint.

[tekktrik]

Sounds good! In that case, the typing looks good!

[makermelissa]

Thanks.