DEP: drop support for Python 3.9, require 3.10 or newer

Author: neutrinoceros

.github/workflows/cibuildwheel.yml

@@ -78,12 +78,12 @@ jobs:
       shell: bash
       # On PRs we run only oldest and newest Python versions to reduce CI load.
       # Skips pypy and musllinux everywhere.
-      # We are building 39, 311 and 314 for now.
+      # We are building 310, 311 and 314 for now.
       # (3.11 is the oldest version for which we support abi3 wheels)
       # These needs to rotate every new Python release.
       run: |
         set -x
-        echo "CIBW_BUILD=cp39-* cp311-* cp314-*" >> $GITHUB_ENV
+        echo "CIBW_BUILD=cp310-* cp311-* cp314-*" >> $GITHUB_ENV
         set +x
 
       if: ${{ github.event_name }} == "pull_request"

.github/workflows/miniconda.yml

@@ -12,7 +12,7 @@ jobs:
     #  NO_NET: 1
     strategy:
       matrix:
-        python-version: [ "3.9", "3.10", "3.11", "3.12", "3.13" ]
+        python-version: [ "3.10", "3.11", "3.12", "3.13" ]
         os: [windows-latest, ubuntu-latest, macos-latest]
         platform: [x64, x32]
         exclude:

pyproject.toml

@@ -12,7 +12,7 @@ description = "Provides an object-oriented python interface to the netCDF versio
 authors = [
   {name = "Jeff Whitaker", email = "whitaker.jeffrey@gmail.com"},
 ]
-requires-python = ">=3.9"
+requires-python = ">=3.10"
 keywords = [
     "numpy", "netcdf", "data", "science", "network", "oceanography",
     "meteorology", "climate",
@@ -21,7 +21,6 @@ license = {text = "MIT"}
 classifiers = [
     "Development Status :: 3 - Alpha",
     "Programming Language :: Python :: 3",
-    "Programming Language :: Python :: 3.9",
     "Programming Language :: Python :: 3.10",
     "Programming Language :: Python :: 3.11",
     "Programming Language :: Python :: 3.12",