Support Python 3.12

.github/workflows/tests.yml

@@ -19,16 +19,16 @@ jobs:
       fail-fast: false
       matrix:
         os: [ubuntu-latest, windows-latest, macos-latest]
-        python-version: ["3.7", "3.11"]
+        python-version: ["3.8", "3.11"]
         include:
           - os: windows-latest
             python-version: "3.9"
           - os: ubuntu-latest
             python-version: "pypy-3.8"
           - os: ubuntu-latest
-            python-version: "3.10"
+            python-version: "3.12.0-beta.1"
           - os: macos-latest
-            python-version: "3.8"
+            python-version: "3.10"
     steps:
       - uses: actions/checkout@v3
       - uses: jupyterlab/maintainer-tools/.github/actions/base-setup@v1

nbformat/sign.py

@@ -14,6 +14,19 @@
 
 try:
     import sqlite3
+
+    # Use adapters recommended by Python 3.12 stdlib docs.
+    # https://docs.python.org/3.12/library/sqlite3.html#default-adapters-and-converters-deprecated
+    def adapt_datetime_iso(val):
+        """Adapt datetime.datetime to timezone-naive ISO 8601 date."""
+        return val.isoformat()
+
+    def convert_datetime(val):
+        """Convert ISO 8601 datetime to datetime.datetime object."""
+        return datetime.fromisoformat(val.decode())
+
+    sqlite3.register_adapter(datetime, adapt_datetime_iso)
+    sqlite3.register_converter("datetime", convert_datetime)
 except ImportError:
     try:
         from pysqlite2 import dbapi2 as sqlite3  # type:ignore[no-redef]

pyproject.toml

@@ -15,19 +15,17 @@ classifiers = [
     "License :: OSI Approved :: BSD License",
     "Programming Language :: Python",
     "Programming Language :: Python :: 3",
-    "Programming Language :: Python :: 3.7",
     "Programming Language :: Python :: 3.8",
     "Programming Language :: Python :: 3.9",
     "Programming Language :: Python :: 3.10",
     "Programming Language :: Python :: 3.11"
 ]
-requires-python = ">=3.7"
+requires-python = ">=3.8"
 dependencies = [
     "fastjsonschema",
     "jsonschema>=2.6",
     "jupyter_core",
-    "traitlets>=5.1",
-    "importlib-metadata>=3.6;python_version<\"3.8\"",
+    "traitlets>=5.1"
 ]
 
 [[project.authors]]
@@ -110,6 +108,8 @@ filterwarnings = [
     "error",
     "ignore:Using or importing the ABCs from 'collections':DeprecationWarning:jsonschema",
     "module:Jupyter is migrating its paths to use standard platformdirs:DeprecationWarning",
+    # ignore pytest warnings.
+    "ignore:::_pytest",
 ]
 
 [tool.coverage.report]