Run pyupgrade with --py37-plus

Fix two places to be py37+ style.

Author: akaihola

.github/workflows/python-package.yml

@@ -109,7 +109,7 @@ jobs:
           from pyupgrade._main import main
           from glob import glob
           files = glob('**/*.py', recursive=True)
-          main(files + ['--py36-plus'])
+          main(files + ['--py37-plus'])
           "
       - name: Check dependencies for known security vulterabilities using Safety
         run: safety check

release_tools/update_contributors.py

@@ -19,7 +19,7 @@
 from itertools import groupby
 from pathlib import Path
 from textwrap import dedent, indent
-from typing import Any, Dict, Iterable, List, MutableMapping, Optional, Text, cast
+from typing import Any, Dict, Iterable, List, MutableMapping, Optional, cast
 
 import click
 import defusedxml.ElementTree
@@ -175,7 +175,7 @@ def request(  # type: ignore[override]  # pylint: disable=arguments-differ
         self,
         method: str,
         url: str,
-        headers: MutableMapping[Text, Text] = None,
+        headers: MutableMapping[str, str] = None,
         **kwargs: Any,
     ) -> Response:
         """Query GitHub API with authorization, caching and host auto-fill-in

src/darker/tests/helpers.py

@@ -2,19 +2,14 @@
 
 import re
 import sys
-from contextlib import contextmanager
+from contextlib import contextmanager, nullcontext
 from types import ModuleType
 from typing import Any, ContextManager, Dict, List, Optional, Union
 from unittest.mock import patch
 
 import pytest
 from _pytest.python_api import RaisesContext
 
-if sys.version_info >= (3, 7):
-    from contextlib import nullcontext
-else:
-    from contextlib import suppress as nullcontext
-
 
 def filter_dict(dct: Dict[str, Any], filter_key: str) -> Dict[str, Any]:
     """Return only given keys with their values from a dictionary"""