Add a tox environment for running mypy

changelog/2431.trivial.rst

@@ -0,0 +1 @@
+Added a tox environment for running mypy.

mypy.ini

@@ -2,7 +2,8 @@
 python_version = 3.9
 pretty = true
 exclude = (?x)(
-          docs
+          docs|
+          .tox
           )
 
 enable_error_code = ignore-without-code

pyproject.toml

@@ -82,19 +82,13 @@ docs = [
   "tox >= 4.4.0",
   "unidecode >= 1.3.6",
 ]
-# Some of these packages contain typing information for packages that
-# don't themselves contain type hints. We might want to move these from
-# the tests section and into the specific mypy environment.
 tests = [
   "hypothesis >= 6.35.1",
-  "pandas-stubs >= 1.5.0.221010",  # used by mypy
   "pre-commit >= 3.0.0",
   "pytest-regressions >= 2.3.1",
   "pytest-xdist >= 3.0.2",
   "tomli >= 2.0.1",
   "tox >= 4.3.1",
-  "types-requests >= 2.27.1",  # used by mypy
-  "types-tqdm >= 4.66.0.3",  # used by mypy
 ]
 [project.urls]
 Changelog = "https://docs.plasmapy.org/en/stable/whatsnew/index.html"

tox.ini

@@ -153,3 +153,9 @@ basepython = python3.9
 extras =
 deps =
 commands = python -c 'import plasmapy'
+
+[testenv:mypy]
+deps =
+    mypy >= 1.8.0
+commands =
+    mypy plasmapy --install-types --non-interactive --show-error-context --show-error-code-links --pretty