Add pyproject-flake8 support (#444)

README.md

@@ -147,6 +147,7 @@ Other dedicated linters that are built-in are:
 | [puppet-lint][puppet-lint]         | `puppet-lint`          |
 | [pycodestyle][pcs-docs]            | `pycodestyle`          |
 | [pydocstyle][pydocstyle]           | `pydocstyle`           |
+| [pyroject-flake8][pflake8]         | `pflake8`              |
 | [Pylint][15]                       | `pylint`               |
 | [Revive][14]                       | `revive`               |
 | [rflint][rflint]                   | `rflint`               |
@@ -429,3 +430,4 @@ busted tests/
 [puppet-lint]: https://github.com/puppetlabs/puppet-lint
 [snyk]: https://github.com/snyk/cli
 [gitlint]: https://github.com/jorisroovers/gitlint
+[pflake8]: https://github.com/csachs/pyproject-flake8

lua/lint/linters/pflake8.lua

@@ -0,0 +1,18 @@
+-- path/to/file:line:col: code message
+local pattern = "[^:]+:(%d+):(%d+):(%w+):(.+)"
+local groups = { "lnum", "col", "code", "message" }
+
+return {
+  cmd = "pflake8",
+  stdin = true,
+  args = {
+    "--format=%(path)s:%(row)d:%(col)d:%(code)s:%(text)s",
+    "--no-show-source",
+    "-",
+  },
+  ignore_exitcode = true,
+  parser = require("lint.parser").from_pattern(pattern, groups, nil, {
+    ["source"] = "flake8",
+    ["severity"] = vim.diagnostic.severity.WARN,
+  }),
+}