Fully support Python 3.12 (#461)

* Use pathlib in test_coding_standards.

* Introduce test_python_versions, including deliberate rollbacks.

* Roll forward Python to 10, 11, 12 in all files.

* Update test_python_versions for macos support.

* Attempt better directory finding.

* Better handling if not running on a git repo.

* Update conda_spec for Tox.

* Catch inconsistencies between tox header and conda_spec.

.github/workflows/ci-locks.yml

@@ -27,7 +27,7 @@ jobs:
       ENV_NAME: "ci-locks"
     strategy:
       matrix:
-        lock: [py39-lock, py310-lock, py311-lock]
+        lock: [py310-lock, py311-lock, py312-lock]
     steps:
     - name: "Checkout"
       uses: actions/checkout@v4
@@ -54,7 +54,7 @@ jobs:
         miniforge-version: latest
         channels: conda-forge,defaults
         activate-environment: ${{ env.ENV_NAME }}
-        auto-update-conda: true 
+        auto-update-conda: true
         use-only-tar-bz2: true
 
     - name: "Conda environment cache"

.github/workflows/ci-tests.yml

@@ -32,17 +32,17 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu-latest]
-        version: [py310, py311]
+        version: [py310, py311, py312]
         gitpath-prepend: [""]
         include:
           - os: ubuntu-latest
             platform: linux
           - os: ubuntu-latest
-            version: py311
+            version: py312
             posargs: "--cov-report=xml --cov"
             post-command: codecov
           - os: macos-latest
-            version: py311
+            version: py312
             platform: osx
             # On macos, the up-to-date git may not be first on the path
             # N.B. setting includes a final ":", to simplify the path setting command

cf_units/tests/test_coding_standards.py

@@ -3,11 +3,10 @@
 # This file is part of cf-units and is released under the BSD license.
 # See LICENSE in the root of the repository for full licensing details.
 
-import os
 import subprocess
 from datetime import datetime
 from fnmatch import fnmatch
-from glob import glob
+from pathlib import Path
 
 import pytest
 
@@ -19,21 +18,18 @@
 # See LICENSE in the root of the repository for full licensing details."""
 
 
-# Guess cf_units repo directory of cf_units - realpath is used to mitigate
-# against Python finding the cf_units package via a symlink.
-DIR = os.path.realpath(os.path.dirname(cf_units.__file__))
-REPO_DIR = os.path.dirname(DIR)
-DOCS_DIR = os.path.join(REPO_DIR, "doc")
-DOCS_DIR = cf_units.config.get_option("Resources", "doc_dir", default=DOCS_DIR)
+REPO_DIR = Path(__file__).resolve().parents[2]
+DOCS_DIR = REPO_DIR / "docs"
+DOCS_DIR = Path(
+    cf_units.config.get_option("Resources", "doc_dir", default=DOCS_DIR)
+)
 exclusion = ["Makefile", "make.bat", "build"]
-DOCS_DIRS = glob(os.path.join(DOCS_DIR, "*"))
-DOCS_DIRS = [
-    DOC_DIR
-    for DOC_DIR in DOCS_DIRS
-    if os.path.basename(DOC_DIR) not in exclusion
-]
+DOCS_DIRS = DOCS_DIR.glob("*")
+DOCS_DIRS = [DOC_DIR for DOC_DIR in DOCS_DIRS if DOC_DIR.name not in exclusion]
+IS_GIT_REPO = (REPO_DIR / ".git").is_dir()
 
 
+@pytest.mark.skipif(not IS_GIT_REPO, reason="Not a git repository.")
 class TestLicenseHeaders:
     @staticmethod
     def whatchanged_parse(whatchanged_output):
@@ -73,10 +69,6 @@ def last_change_by_fname():
             or cannot be found by subprocess, an IOError may also be raised.
 
         """
-        # Check the ".git" folder exists at the repo dir.
-        if not os.path.isdir(os.path.join(REPO_DIR, ".git")):
-            raise ValueError("{} is not a git repository.".format(REPO_DIR))
-
         # Call "git whatchanged" to get the details of all the files and when
         # they were last changed.
         output = subprocess.check_output(
@@ -100,20 +92,14 @@ def test_license_headers(self):
             "cf_units/_udunits2_parser/parser/*",
         )
 
-        try:
-            last_change_by_fname = self.last_change_by_fname()
-        except ValueError:
-            # Caught the case where this is not a git repo.
-            return pytest.skip(
-                "cf_units installation did not look like a " "git repo."
-            )
+        last_change_by_fname = self.last_change_by_fname()
 
         failed = False
         for fname, last_change in sorted(last_change_by_fname.items()):
-            full_fname = os.path.join(REPO_DIR, fname)
+            full_fname = REPO_DIR / fname
             if (
-                full_fname.endswith(".py")
-                and os.path.isfile(full_fname)
+                full_fname.suffix == ".py"
+                and full_fname.is_file()
                 and not any(fnmatch(fname, pat) for pat in exclude_patterns)
             ):
                 with open(full_fname) as fh:
@@ -129,3 +115,93 @@ def test_license_headers(self):
             raise AssertionError(
                 "There were license header failures. See stdout."
             )
+
+
+@pytest.mark.skipif(not IS_GIT_REPO, reason="Not a git repository.")
+def test_python_versions():
+    """Confirm alignment of ALL files listing supported Python versions."""
+    supported = ["3.10", "3.11", "3.12"]
+    supported_strip = [ver.replace(".", "") for ver in supported]
+    supported_latest = supported_strip[-1]
+
+    workflows_dir = REPO_DIR / ".github" / "workflows"
+
+    # Places that are checked:
+    pyproject_toml_file = REPO_DIR / "pyproject.toml"
+    setup_cfg_file = REPO_DIR / "setup.cfg"
+    tox_file = REPO_DIR / "tox.ini"
+    ci_locks_file = workflows_dir / "ci-locks.yml"
+    ci_tests_file = workflows_dir / "ci-tests.yml"
+    ci_wheels_file = workflows_dir / "ci-wheels.yml"
+
+    text_searches: list[tuple[Path, str]] = [
+        (
+            pyproject_toml_file,
+            "target-version = ["
+            + ", ".join([f'"py{p}"' for p in supported_strip])
+            + "]",
+        ),
+        (
+            setup_cfg_file,
+            "\n    ".join(
+                [
+                    f"Programming Language :: Python :: {ver}"
+                    for ver in supported
+                ]
+            ),
+        ),
+        (
+            tox_file,
+            "[testenv:py{" + ",".join(supported_strip) + "}-lock]",
+        ),
+        (
+            tox_file,
+            "[testenv:py{"
+            + ",".join(supported_strip)
+            + "}-{linux,osx,win}-test]",
+        ),
+        (
+            ci_locks_file,
+            "lock: ["
+            + ", ".join([f"py{p}-lock" for p in supported_strip])
+            + "]",
+        ),
+        (
+            ci_tests_file,
+            (
+                f"os: [ubuntu-latest]\n"
+                f"{8*' '}version: ["
+                + ", ".join([f"py{p}" for p in supported_strip])
+                + "]"
+            ),
+        ),
+        (
+            ci_tests_file,
+            (f"os: ubuntu-latest\n" f"{12*' '}version: py{supported_latest}"),
+        ),
+        (
+            ci_tests_file,
+            (f"os: macos-latest\n" f"{12*' '}version: py{supported_latest}"),
+        ),
+    ]
+
+    # This routine will not check for file existence first - if files are
+    #  being added/removed we want developers to be aware that this test will
+    #  need to be updated.
+    for path, search in text_searches:
+        assert search in path.read_text()
+
+    tox_text = tox_file.read_text()
+    for version in supported_strip:
+        # A fairly lazy implementation, but should catch times when the section
+        #  header does not match the conda_spec for the `tests` section.
+        #  (Note that Tox does NOT provide its own helpful error in these cases).
+        py_version = f"py{version}"
+        assert tox_text.count(f"    {py_version}-") == 3
+        assert tox_text.count(f"{py_version}-lock") == 3
+
+    ci_wheels_text = ci_wheels_file.read_text()
+    (cibw_line,) = [
+        line for line in ci_wheels_text.splitlines() if "CIBW_SKIP" in line
+    ]
+    assert all([p not in cibw_line for p in supported_strip])

pyproject.toml

@@ -47,7 +47,7 @@ local_scheme = "dirty-tag"
 
 [tool.black]
 line-length = 79
-target-version = ["py39", "py310", "py311"]
+target-version = ["py310", "py311", "py312"]
 include = '\.pyi?$'
 exclude = '''
 (

setup.cfg

@@ -6,9 +6,9 @@ classifiers =
     License :: OSI Approved :: BSD License
     Operating System :: OS Independent
     Programming Language :: Python :: 3 :: Only
-    Programming Language :: Python :: 3.9
     Programming Language :: Python :: 3.10
     Programming Language :: Python :: 3.11
+    Programming Language :: Python :: 3.12
     Topic :: Scientific/Engineering
 description = Units of measure as required by the Climate and Forecast (CF) metadata conventions
 download_url = https://github.com/SciTools/cf-units

tox.ini

@@ -2,8 +2,8 @@
 requires =
     tox-conda
     tox-run-command
- 
- 
+
+
 [testenv:py{310,311,312}-lock]
 allowlist_externals =
     cp
@@ -34,15 +34,15 @@ commands =
 
 [testenv:py{310,311,312}-{linux,osx,win}-test]
 conda_spec =
-    py39-linux: {toxinidir}{/}requirements{/}locks{/}py39-lock-linux-64.txt
     py310-linux: {toxinidir}{/}requirements{/}locks{/}py310-lock-linux-64.txt
     py311-linux: {toxinidir}{/}requirements{/}locks{/}py311-lock-linux-64.txt
-    py39-osx: {toxinidir}{/}requirements{/}locks{/}py39-lock-osx-64.txt
+    py312-linux: {toxinidir}{/}requirements{/}locks{/}py312-lock-linux-64.txt
     py310-osx: {toxinidir}{/}requirements{/}locks{/}py310-lock-osx-64.txt
     py311-osx: {toxinidir}{/}requirements{/}locks{/}py311-lock-osx-64.txt
-    py39-win: {toxinidir}{/}requirements{/}locks{/}py39-lock-win-64.txt
+    py312-osx: {toxinidir}{/}requirements{/}locks{/}py312-lock-osx-64.txt
     py310-win: {toxinidir}{/}requirements{/}locks{/}py310-lock-win-64.txt
     py311-win: {toxinidir}{/}requirements{/}locks{/}py311-lock-win-64.txt
+    py312-win: {toxinidir}{/}requirements{/}locks{/}py312-lock-win-64.txt
 description =
     Perform cf-units unit/integration tests.
 passenv =