Support ignore patterns for formatters

[iutlu]

Currently there's an option for linters that allows files to be excluded (python.linting.ignorePatterns), but there's not a similar option for formatters as far as I can see.

Would it be possible to implement a similar python.formatting.ignorePatterns, so that we can configure VSCode to not format, e.g., files from the standard library, or 3rd party packages? In my experiments, the Python extension does invoke the formatter for files in site-packages. I think it's more valuable to protect those kinds of files against accidental formatting, rather than accidental linting.

There's a similar issue at microsoft/vscode-python#7047, but that one's about black's inability to hard-exclude files (including files passed on the command line). I'm interested in not invoking the formatter in the first place.

[brettcannon]

Thank you for the suggestion! We have marked this issue as "needs decision" to make sure we have a conversation about your idea. We plan to leave this feature request open for at least a month to see how many 👍 votes the opening comment gets to help us make our decision.

[limonkufu]

I also need this, I think this would be very useful

[mathieucaroff]

It would be useful to me to be able formatting-ignore the files under /site-packages/, as I put breakpoints there and I don't want these files formatted when I save.

[brettcannon]

Black supports # fmt: off markers to turn formatting off. It also supports --exclude and --extend-exclude options to control what files to format. And you can turn off the extension per-workspace or use profiles if you don't want to use it in other situations if you have configured Black as your formatter and turned on format-on-save universally instead of per-project.

[karthiknadig]

Black extension works with --force-exclude black option, closing this in favor of that CLI option.
related: #360