Description

pablogsal

opened on Dec 4, 2023

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This has several advantages:

• Will help a lot with readability as parsing the error lines is easier if color highlights the error ranges.
• In the future we can optionally (via config) drop the ranges and only use color, recovering back the extra lines that the carets are taking.
• All the cool kids are doing it: This feature has already been successfully implemented in various tools. It has proven to be an effective aid for developers in quickly identifying the source and location of errors.

Control features:

• The feature will use 16 ANSI color scapes so the actual color is configured via the terminal emulator.
• Users can set the following env vars to control it (in the following order):
  • PY_COLORS=1 activates the feature (used by pytest: https://github.com/pytest-dev/pytest/blob/022f1b4de546c8b3529e071965555888ecf01cb4/src/_pytest/_io/terminalwriter.py#L28)
  • PY_COLORS=0 deactivates the feature
  • NO_COLOR=1 deactivates the feature
  • FORCE_COLOR=1 activates the feature
  • Feature is deactivated if terminal is not a tty or if TERM is set to dumb.

Linked PRs

• gh-112730: Use color to highlight error locations #112732
• gh-112730: Update docs for colour env vars #112837
• gh-112730: Make the test suite resilient to color-activation environment variables #117672
• gh-112730: use keyword only argument for colorize #118086
• gh-112730: Respect tests that require environment variables with no-colorize fixes #118288

Reacted by André Roberge, Rajarishi Devarajan, tuxayo and Yashas G V

Reacted by Hugo van Kemenade, Kirill Podoprigora, Erlend E. Aasland, baggiponte, itzAkari, Mohamed El Mouctar Haidara, Alex Waygood, Rajarishi Devarajan and tuxayo

Activity

1. pablogsal

   added 2 commits that reference this issue on Dec 4, 2023

   pythongh-112730: Use color to highlight error locations

   b0d9a03

   pythongh-112730: Use color to highlight error locations

   bc6e729
2. pablogsal

   assigned

   ambv

   and unassigned

   ambv

   on Dec 4, 2023
3. pablogsal

   added 6 commits that reference this issue on Dec 4, 2023

   pythongh-112730: Use color to highlight error locations

   c40cb47

   pythongh-112730: Use color to highlight error locations

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   pythongh-112730: Use color to highlight error locations

   2fc1050

   pythongh-112730: Use color to highlight error locations

   182fae6

   pythongh-112730: Use color to highlight error locations

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   pythongh-112730: Use color to highlight error locations

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4. hugovk commented on Dec 5, 2023

   

   hugovk

   on Dec 5, 2023

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   This looks really good, thanks!

   Perhaps something for a followup, can we customise the colouring a bit?

   PR #112732 right now:

   

   GitHub / MagicPython

   GitHub markdown (with pytb after the triple backticks):

   Traceback (most recent call last):
     File "/Users/hugo/github/python/cpython/main/1.py", line 1, in <module>
       1/0
       ~^~
   ZeroDivisionError: division by zero

   (GitHub screenshot)

   

   (Uses https://github.com/MagicStack/MagicPython for Python tracebacks: https://github.com/github-linguist/linguist/blob/master/vendor/README.md)

   Sphinx / pygments

   Sphinx with .. code-block:: pytb, for example on the PEPs repo:

   

   (Uses Pygments' Native style)
5. pablogsal commented on Dec 5, 2023

   

   pablogsal

   on Dec 5, 2023

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   Perhaps something for a followup, can we customise the colouring a bit?

   Yup, see #112732 (comment).

   I want to explore customization options AFTER we land the basic version first. EDIT Or are you referring to customizing the coloring as "adding more colors"?

   On the other hand, are you suggesting to also colorize the name of the exception, the file, the number and the Traceback text?

   I have been told that yellow and cian are really bad for light mode, so we should do something else there.
6. pablogsal commented on Dec 5, 2023

   

   pablogsal

   on Dec 5, 2023

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   @hugovk What about like this?

   
   
7. hugovk commented on Dec 5, 2023

   

   hugovk

   on Dec 5, 2023

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   I wasn't thinking about allowing the user to customise them (although that's something to consider) but about having different colours for the different elements (exception name, file, etc).

   Yes, we should check the contrast is good for both light and dark modes.

   The GitHub colours (ignoring the plain black/white text) look the same for each mode and display well for both:

   

   

   edit: and the blues are different, but you get the idea :)
8. pablogsal commented on Dec 5, 2023

   

   pablogsal

   on Dec 5, 2023

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   I am quite colorblind myself 😅 Do you mind telling me what colors are supposed to be every piece? As in "filename is ..., line number is ...., function name is ..., source code is ..., error location is ...)

   Reacted by Hugo van Kemenade
9. 19 remaining items

10. pablogsal commented on Apr 8, 2024

    

    pablogsal

    on Apr 8, 2024

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    Maybe we could just add a support decorator that just does the appropriate monkey patching in the colorise function to avoid being affected by the force colours variable. To avoid regressions, setting FORCE_COLORS in GH actions sounds like a good idea.

    Reacted by Alex Waygood
11. pablogsal commented on Apr 8, 2024

    

    pablogsal

    on Apr 8, 2024

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    I personally think it's very useful for Python to use the same env vars that are being increasingly widely adopted elsewhere. So I suppose I lean towards changing -E so that it also ignores the FORCE_COLOR variable.

    I think if we don't do this it's going to be a full pain for us and a lot of users that have the variable set in CI and are running subprocesses in tests
12. pablogsal

    added a commit that references this issue on Apr 9, 2024

    pythongh-112730: Make the test suite relient to color-activation envi…

    e08e26c
13. methane

    added 2 commits that reference this issue on Apr 19, 2024

    pythongh-112730: use keyword only argument for colorize

    3f59131

    pythongh-112730: use keyword only argument for colorize

    d48bfc3
14. pablogsal

    added a commit that references this issue on Apr 24, 2024

    gh-112730: Make the test suite resilient to color-activation environm…

    345e1e0
15. encukou commented on Apr 25, 2024

    

    encukou

    on Apr 25, 2024

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    #117672 broke several stable buildbots, see e.g. here. As Jakub noted they seem to be --enable-shared builds that rely on LD_LIBRARY_PATH to find libpython.

    Do you have time to look into this?
16. pablogsal commented on Apr 25, 2024

    

    pablogsal

    on Apr 25, 2024

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    I will look into this today. We can revert in the meanwhile if you wish
17. pablogsal

    added 2 commits that reference this issue on Apr 25, 2024

    pythongh-112730: Respect tests that require environment variables wit…

    5db08d0

    gh-112730: Respect tests that require environment variables with no-c…

    b43c7e1
18. pablogsal commented on Apr 26, 2024

    

    pablogsal

    on Apr 26, 2024

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    I think this will be fixed by #118288

    Reacted by Petr Viktorin
19. hugovk commented on Jun 15, 2024

    

    hugovk

    on Jun 15, 2024

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    #118288 has been merged, closing.
20. hugovk

    closed this as completedon Jun 15, 2024
21. Glyphack

    added 2 commits that reference this issue on Sep 2, 2024

    pythongh-112730: Use color to highlight error locations (pythongh-112732

    37e5f1e

    pythongh-112730: Update docs for colour env vars (python#112837)

    5e33ba2

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