python.linting.flake8CategorySeverity.F should default to "Warning", not "Error"

[danvk]

(Moving over from microsoft/vscode#43851)

With flake8, the "F*" issues are labeled as errors by default (https://code.visualstudio.com/docs/python/linting#_flake8).

I think this comes from a misunderstanding of what "F" (vs. "W" or "E") means in this context. For flake8, it means that these are issues flagged by pyflakes, rather than that these are fatal errors. See http://flake8.pycqa.org/en/latest/glossary.html#term-class

The upshot is that issues like unused imports are flagged as errors by default with pyflake, rather than as warnings. They should be warnings:

{
  "python.linting.flake8CategorySeverity.F": "Warning"
}

• VSCode Version: Version 1.19.2 (1.19.2)
• OS Version: macOS Sierra 10.12.6 (16G29)

[MikhailArkhipov]

7894ae6

[brettcannon]

I'm re-opening this issue as this shifts things for all flake8 checkers since the E class of errors come from pycodestyle which are stylistic and not actual errors either. So if we're now shifting F to be warnings then E should be as well and the only thing that should be an error is E999 errors.

[brettcannon]

There's also the issue that only some of the pyflakes errors are not errors in the classical sense. For instance, all of the F7 codes are actual errors. There's also the issue that E999 is the catch-all error for syntax errors, but the rest of the E rules are actually from pycodestyle which are definitely not errors.