chore: add PyLint and fix most issues (#999)

* chore: add PyLint and fix most issues

* fix: minor fixes after first push

* chore: remove reference to old toml lib

* chore: minor options cleanup

* ci: only fail with many pylint issues, annotate in GHA

* refactor: address review

* ci: force nox to report in CI

* refactor: use map instead of if chain

* refactor: simpler shell_with_arch

* refactor: even simpler shell_with_arch

* Restore if...elif...else blocks where guard-style is not intended

Co-authored-by: Joe Rickerby <joerick@mac.com>

noxfile.py

@@ -1,15 +1,19 @@
+import os
 import shutil
 import sys
 from pathlib import Path
 
 import nox
 
-nox.options.sessions = ["lint", "check_manifest", "tests"]
+nox.options.sessions = ["lint", "pylint", "check_manifest", "tests"]
 
 PYTHON_ALL_VERSIONS = ["3.6", "3.7", "3.8", "3.9", "3.10"]
 
 DIR = Path(__file__).parent.resolve()
 
+if os.environ.get("CI", None):
+    nox.options.error_on_missing_interpreters = True
+
 
 @nox.session
 def tests(session: nox.Session) -> None:
@@ -34,6 +38,16 @@ def lint(session: nox.Session) -> None:
     session.run("pre-commit", "run", "--all-files", *session.posargs)
 
 
+@nox.session
+def pylint(session: nox.Session) -> None:
+    """
+    Run pylint.
+    """
+
+    session.install("pylint", ".")
+    session.run("pylint", "cibuildwheel", *session.posargs)
+
+
 @nox.session
 def check_manifest(session: nox.Session) -> None:
     """