confusion over importing modules that python supports but micropython does not.
gilesknap opened this issue · 14 comments
Please provide a clear and concise description of the bug along with logs
What are the steps to reproduce this issue?
- put
from typing import Callablein a .py file and attempt to run it
What happens?
There are no static code check errors (so no red squiggles) but upon execution I see:
ImportError: no module named 'typing'
What were you expecting to happen?
That I'm able to supply type hints for Callables
Any other comments?
I'm pretty sure that the typing module is not available in micropython but I'm confused by the fact that I see its use in .vscode/Pico-W-Stub/machine.pyi.
This happens with some other modules too. I get no linting errors but when I go to execute the code I then get a runtime error. Perhaps the issue is that I need to uninstall the Pylance Extension?
Which version of MicroPico are you using?
v3.5.0
Support info
Version: 1.84.2
Commit: 1a5daa3a0231a0fbba4f14db7ec463cf99d7768e
Date: 2023-11-09T10:50:47.800Z
Electron: 25.9.2
ElectronBuildId: 24603566
Chromium: 114.0.5735.289
Node.js: 18.15.0
V8: 11.4.183.29-electron.0
OS: Linux x64 6.2.0-37-generic
@Josverl I think that's something concerning Josverl/micropython-stubs...
(I'm unable to transfer the issue for some reason)
Currently micropython firmware does not include the typing modules. There is a PR on micropython-lib to add it, but there is a conversation on the additional byte cost of that.
What I personally do is add a typing library to my source during development.
See: https://github.com/Josverl/MicroPicoDMX/tree/main/src%2Flib
I should possibly document that workaround.
So technically this is not a bug, but a lack of an assumed feature 🙃
@Josverl thanks - I'm not sure I fully get how to implement your workaround. Does it really enable type checking or just allow you to use code that has type hints?
@paulober in general how do I tell if a module that I import really exists in MicroPython? I seem to find that linting lets me import many things that don't work at runtime. import enum is another example.
@paulober in general how do I tell if a module that I import really exists in MicroPython? I seem to find that linting lets me import many things that don't work at runtime.
import enumis another example.
Running 'import module' in the vREPL. If it shows you an import error, the module is not available. And generally modules starting with u should be a micropython module.
Does it really enable type checking or just allow you to use code that has type hints?
well - type checing in python is optional - so not real type-checking as in a early-bound language
also I aim to make the MicroPython type-stubs "not wrong "rather than "always right", and even that is not simple
I think your issues import enum is caused by the fact that the stubs also include a simplified version of the stdlib type-stubs
and they in turn include , and depend on a the enum.pyi type stub.
I maintain an overview of the modules on the different ports and boards : enum is not there
https://flatgithub.com/Josverl/micropython-stubs/?filename=all_modules.json
if you find other modules that you find misleading , please feel free to raise an issue on https://github.com/Josverl/micropython-stubs/
@gilesknap I have published a pre-release of micropython-stdlib-stubs (1.0.1a0)
you can install ( adjust the target location for your setup )
pip install micropython-stdlib-stubs --pre --target typings --no-user
Can you please let me know in the linked issue if this solves your problem , and if you think additional work is needed ?
Also, I would appreciate if you can share a snippet of the code to reproduce / show the problem , so I can add that to the QA testing to maintain quality in future updates to stdlib
Hey thanks! taking a look now.
@gilesknap , FYI I documented the Why and how :
https://micropython-stubs.readthedocs.io/en/main/_typing_mpy.html,
@gilesknap I Fuß the issue can be closed now?
sure, thanks!