drop support for Python 3.6

Python 3.8 is now the minimum version

Author: mr-c

.github/workflows/ci-tests.yml

@@ -15,23 +15,14 @@ jobs:
   tox:
     name: CI tests via Tox
 
-    runs-on: ubuntu-20.04  # 22.04 doesn't support Python 3.6
+    runs-on: ubuntu-22.04
 
     strategy:
       matrix:
         py-ver-major: [3]
-        py-ver-minor: [6, 8, 9, 10, 11, 12]
+        py-ver-minor: [8, 9, 10, 11, 12]
         step: [lint, bandit, unit, mypy, memleak]
         exclude:
-          - py-ver-major: 3
-            py-ver-minor: 6
-            step: mypy
-          - py-ver-major: 3
-            py-ver-minor: 6
-            step: memleak
-          - py-ver-major: 3
-            py-ver-minor: 6
-            step: lint
           - py-ver-major: 3
             py-ver-minor: 12
             step: memleak

CONTRIBUTING.md

@@ -1,5 +1,5 @@
 Style guide:
-- Python 3.6+ compatible code
+- Python 3.8+ compatible code
 - PEP-484 type hints
 - Prefer new style format strings https://pyformat.info/
 - Use ``make format`` to format your code

Makefile

@@ -178,9 +178,6 @@ mypy3: mypy
 mypy: $(filter-out setup.py,$(PYSOURCES))
 	MYPYPATH=$$MYPYPATH:mypy-stubs mypy $^
 
-mypy_3.6: $(filter-out setup.py,$(PYSOURCES))
-	MYPYPATH=$$MYPYPATH:mypy-stubs mypy --python-version 3.6 $^
-
 mypyc: $(PYSOURCES)
 	MYPYPATH=mypy-stubs SCHEMA_SALAD_USE_MYPYC=1 pip install --verbose -e . \
 		 && pytest "${PYTEST_EXTRA}"
@@ -206,7 +203,8 @@ shellcheck: FORCE
 	shellcheck build-schema_salad-docker.sh release-test.sh
 
 pyupgrade: $(filter-out schema_salad/metaschema.py,$(PYSOURCES))
-	pyupgrade --exit-zero-even-if-changed --py36-plus $^
+	pyupgrade --exit-zero-even-if-changed --py38-plus $^
+	auto-walrus $^
 
 release-test: FORCE
 	git diff-index --quiet HEAD -- || ( echo You have uncommitted changes, please commit them and try again; false )

README.rst

@@ -23,7 +23,7 @@ generation, and transformation to RDF_. Salad provides a bridge
 between document and record oriented data modeling and the Semantic
 Web.
 
-The Schema Salad library is Python 3.6+ only.
+The Schema Salad library is Python 3.8+ only.
 
 Installation
 ------------

dev-requirements.txt

@@ -9,3 +9,4 @@ isort < 5.13
 build < 0.10.1
 autoflake < 2.3
 bandit < 1.7.6
+auto-walrus

pyproject.toml

@@ -2,8 +2,7 @@
 requires = [
     "setuptools>=45",
     "setuptools_scm[toml]>=6.2",
-    'mypy==0.971; python_version == "3.6"',  # last version for Python 3.6
-    'mypy==1.4.1; python_version >= "3.7"',  # update mypy-requirements as well
+    'mypy==1.4.1',  # update mypy-requirements as well
     "black>=19.10b0",
     "types-pkg_resources",
     "types-requests",
@@ -22,11 +21,11 @@ before-build = "python -m pip install -r requirements.txt -r mypy-requirements.t
 test-command = "python -m pytest -n 2 --junitxml=/output/test-results/junit_$(python -V | awk '{print $2}')_${AUDITWHEEL_PLAT}.xml --pyargs schema_salad"
 test-requires = "-r test-requirements.txt"
 test-extras = "pycodegen"
-skip = "pp* cp36-*"
+skip = "pp* cp36-* cp37-* cp312-*"
 #      ^ skip building wheels on PyPy (any version)
-#           ^ skip building wheels on Python 3.6 (we now need mypy 0.990+ which doesn't support Python 3.6)
+#           ^ skip building wheels on Python 3.6 / 3.7 (not supported) & 3.12 (not ready)
 build-verbosity = "1"
 
 [tool.black]
 line-length = 100
-target-version = [ "py36" ]
+target-version = [ "py38" ]

requirements.txt

@@ -1,15 +1,9 @@
 requests >= 1.0
-ruamel.yaml >= 0.16.12, < 0.18
-ruamel.yaml >= 0.17.6;python_version>='3.7'
+ruamel.yaml >= 0.17.6, < 0.18
 rdflib>= 4.2.2, < 7.0.0
-rdflib< 6.0.0;python_version<='3.6'
-rdflib-jsonld>=0.4.0, <= 0.6.1;python_version<='3.6'
 mistune>=2.0.3,<2.1
 CacheControl[filecache]>= 0.11.7, < 0.14
-CacheControl[filecache]< 0.13;python_version<='3.6'
-urllib3<2;python_version<='3.6'
 black<23.8
 mypy_extensions
-importlib_metadata;python_version<'3.8'
 importlib_resources>=1.4
 # ^^ equivalent to Python 3.9

schema_salad/codegen.py

@@ -59,7 +59,7 @@ def codegen(
     info = parser_info or pkg
     salad_version = schema_metadata.get("saladVersion", "v1.1")
 
-    if lang in set(["python", "cpp", "dlang"]):
+    if lang in {"python", "cpp", "dlang"}:
         if target:
             dest: Union[TextIOWrapper, TextIO] = open(target, mode="w", encoding="utf-8")
         else:

schema_salad/main.py

@@ -22,10 +22,8 @@
 if int(rdflib_version.split(".", maxsplit=1)[0]) < 6:
     register("json-ld", Parser, "rdflib_jsonld.parser", "JsonLDParser")
 
-if sys.version_info >= (3, 8):
-    import importlib.metadata as importlib_metadata
-else:
-    import importlib_metadata
+import importlib.metadata
+
 _logger = logging.getLogger("salad")
 
 
@@ -225,8 +223,7 @@ def main(argsl: Optional[List[str]] = None) -> int:
     if args.debug:
         _logger.setLevel(logging.DEBUG)
 
-    pkg = importlib_metadata.version("schema_salad")
-    if pkg:
+    if pkg := importlib.metadata.version("schema_salad"):
         if args.version:
             print(f"{sys.argv[0]} Current version: {pkg}")
             return 0

schema_salad/sourceline.py

@@ -85,8 +85,7 @@ def indent(v: str, nolead: bool = False, shift: str = "  ", bullet: str = "  ")
         return v.splitlines()[0] + "\n".join([shift + line for line in v.splitlines()[1:]])
 
     def lineno(i: int, line: str) -> str:
-        r = lineno_re.match(line)
-        if r is not None:
+        if (r := lineno_re.match(line)) is not None:
             group1 = r.group(1)
             group2 = r.group(2)
             assert group1 is not None  # nosec