chore: drop python 2 support and run test in PRs

[MaferMazu]

Description

This PR edits and removes functions related to Python 2—all the corrections were made based on searching for Python 2 comments in the code.

Related to #326

Note

I think it is easier to review this PR by commit.

Details

• Remove Python 2 condition from tests/helpers/test_compatibility.py
• Use reload from importlib.
• Use mock from unittest and not from helpers for clarity and correctness.
• Remove ValueError try-except from mitxgraders/helpers/calc/robust_pow.py.
• Remove the text_string function, that was created for Python 2.
• Remove get_number_of_args_py2 function.
• Use get_number_of_args_py3 in get_number_of_args.
• Remove get_builtin_positional_args_py2 because it is no longer used in get_number_of_args_py2.
• Remove the ensure_text function because was used to maintain compatibility with Python 2.
• Remove the UNICODE_PREFIX variable used for Python 2.
• Refactor format_message_with_locations.

How to test

Code

All the checks are passed.

Integration:

Environment

• Have a tutor environment with Tutor v18.1.4
• Install codejail. You can follow the installation and usage process from the tutor-contrib-codejail README.
• Perform a dev launch

Data

• Import the MIT demo course running:

tutor dev do importdemocourse -r https://github.com/mitodl/mitx-grading-library -d course -v master

For more info: tutor dev do importdemocourse -h

• Create an admin user

tutor dev do createuser --staff --superuser admin [email protected]

Test

1. Enter in Studio > MITx Grading Library > Content > Files
2. Remove the python_lib.zip and add this one:
   python_lib.zip

Note

If you want to create your python_lib from this version, you can clone the repo, enter in it, and then:

find mitxgraders voluptuous -type f ! -path "*/__pycache__/*" | zip python_lib.zip -@

3. Make sure the units are rendered and worked well.

[jolyonb]

I've approved the other PR. When that's merged and you've rebased this on top of master and pushed again, I'll review this :)

[jolyonb]

Okay, I've worked my way through all the commits (thanks for the suggestion).

I'm okay with just merging this as-is, but beware that you're still going to need to remove the six library in a future PR.

Also, I'm concerned that the github actions are no longer running our unit tests... that seems bad? (probably good to fix that in another PR too).

[jolyonb]

Please fix the github actions unit tests next!

[MaferMazu]

I added the fix for the GitHub action to have the testing here and ensure everything works well.

I'll merge this. Thanks @jolyonb.