chore: drop py3.9, touch up readme

.github/workflows/ci.yml

@@ -77,7 +77,7 @@ jobs:
       fail-fast: false
       matrix:
         os: [ ubuntu-22.04, macos-13, windows-2022 ]
-        python: [ 3.9, "3.10", "3.11", "3.12", "3.13" ]
+        python: [ "3.10", "3.11", "3.12", "3.13" ]
     env:
       GCC_V: 11
     steps:
@@ -167,7 +167,7 @@ jobs:
         # only invoke the GH API on one OS and Python version
         # to avoid rate limits (1000 rqs / hour / repository)
         # https://docs.github.com/en/actions/learn-github-actions/usage-limits-billing-and-administration#usage-limits
-        if: runner.os == 'Linux' && matrix.python == '3.9'
+        if: runner.os == 'Linux' && matrix.python == '3.10'
         working-directory: modflow-devtools/autotest
         env:
           REPOS_PATH: ${{ github.workspace }}

DEVELOPER.md

@@ -19,7 +19,7 @@ This document provides guidance to set up a development environment and discusse
 
 ## Requirements
 
-Python3.9+ is currently required. This project supports several recent versions of Python, loosely following [NEP 29](https://numpy.org/neps/nep-0029-deprecation_policy.html#implementation) and aiming to stay synchronized with [FloPy](https://github.com/modflowpy/flopy).
+Python3.10+ is currently required. This project has historically aimed to support several recent versions of Python, loosely following [NEP 29](https://numpy.org/neps/nep-0029-deprecation_policy.html#implementation). In current and future development this window may narrow to follow [SPEC 0](https://scientific-python.org/specs/spec-0000/#support-window) instead.
 
 ## Installation
 

README.md

@@ -18,7 +18,7 @@
 <!-- START doctoc generated TOC please keep comment here to allow auto update -->
 <!-- DON'T EDIT THIS SECTION, INSTEAD RE-RUN doctoc TO UPDATE -->
 
-Python development tools for MODFLOW 6.
+Python development tools for MODFLOW 6 and related projects.
 
 - [Use cases](#use-cases)
 - [Requirements](#requirements)
@@ -27,36 +27,28 @@ Python development tools for MODFLOW 6.
 
 <!-- END doctoc generated TOC please keep comment here to allow auto update -->
 
-## Use cases
+## Features
 
-This is a small toolkit for developing MODFLOW 6, FloPy, and related projects. It includes standalone utilities and optional [Pytest](https://github.com/pytest-dev/pytest) extensions.
-
-Utilities include:
-
-* a minimal GitHub API client for retrieving release information and downloading assets
+* a minimal GitHub API client for release info/assets
 * a `ZipFile` subclass that [preserves file permissions](https://stackoverflow.com/questions/39296101/python-zipfile-removes-execute-permissions-from-binaries) (workaround for [Python #15795](https://bugs.python.org/issue15795))
-* other release/distribution-related tools
-
-Pytest features include:
-
-- `--keep <path>` tempdir fixtures for [each scope](https://docs.pytest.org/en/stable/how-to/fixtures.html#scope-sharing-fixtures-across-classes-modules-packages-or-session)
-- a [`--smoke` test](https://en.wikipedia.org/wiki/Smoke_testing_(software)) (abbrev. `-S`) CLI option shortcut
-- markers to skip test cases conditional on
-  - operating system
-  - Python packages installed
-  - executables available on the PATH
-- test fixtures for example / test models in
-  - `MODFLOW-ORG/modflow6-examples`
-  - `MODFLOW-ORG/modflow6-testmodels`
-  - `MODFLOW-ORG/modflow6-largetestmodels`
+* pytest fixtures including "keepable" tempdirs
+* pytest markers to skip test cases conditional on operating system, installed packages, or available executables
+* a parser for MODFLOW 6 [definition files](https://modflow6.readthedocs.io/en/stable/_dev/dfn.html)
+* streamlined access to MODFLOW 6 models in
+  - [`MODFLOW-ORG/modflow6-examples`](https://github.com/MODFLOW-ORG/modflow6-examples)
+  - [`MODFLOW-ORG/modflow6-testmodels`](https://github.com/MODFLOW-ORG/modflow6-testmodels)
+  - [`MODFLOW-ORG/modflow6-largetestmodels`](https://github.com/MODFLOW-ORG/modflow6-largetestmodels)
+* a parser for MODFLOW 6 [definition files](https://modflow6.readthedocs.io/en/stable/_dev/dfn.html)
 
 ## Requirements
 
-Python3.9+, dependency-free, but pairs well with `pytest` and select plugins, e.g.
+Python3.10+, dependency-free by default.
+
+Several optional dependency groups are available, oriented around specific use cases:
 
-- [`pytest-dotenv`](https://github.com/quiqua/pytest-dotenv)
-- [`pytest-xdist`](https://github.com/pytest-dev/pytest-xdist)
-- [`syrupy`](https://github.com/tophat/syrupy)
+- `dfn`: MF6 definition file parsing
+- `test`: pytest fixtures/extensions
+- `models`: example model access
 
 ## Installation
 
@@ -66,15 +58,15 @@ Python3.9+, dependency-free, but pairs well with `pytest` and select plugins, e.
 pip install modflow-devtools
 ```
 
-Pytest, pytest plugins, and other testing-related dependencies can be installed with:
+To install an optional dependency group:
 
 ```shell
 pip install "modflow-devtools[test]"
 ```
 
 To install from source and set up a development environment please see the [developer documentation](DEVELOPER.md).
 
-To import `pytest` fixtures in a project consuming `modflow-devtools`, add the following to a test file or `conftest.py` file:
+To use the `pytest` fixtures provided by `modflow-devtools`, add the following to a test file or `conftest.py` file:
 
 ```python
 pytest_plugins = [ "modflow_devtools.fixtures" ]

autotest/test_models.py

@@ -10,11 +10,6 @@
 MODELS_TOML_PATH = Path(models.DATA_PATH) / models.MODELMAP_NAME
 
 
-# TODO: Remove when we drop support for python 3.9 (soon?)
-if sys.version_info[:2] == (3, 9):
-    pytest.skip("Unsupported for python 3.9", allow_module_level=True)
-
-
 @pytest.fixture
 def models_toml():
     with MODELS_TOML_PATH.open("rb") as f:

pyproject.toml

@@ -29,14 +29,13 @@ classifiers = [
     "License :: CC0 1.0 Universal (CC0 1.0) Public Domain Dedication",
     "Programming Language :: Python :: 3 :: Only",
     "Programming Language :: Python :: 3",
-    "Programming Language :: Python :: 3.9",
     "Programming Language :: Python :: 3.10",
     "Programming Language :: Python :: 3.11",
     "Programming Language :: Python :: 3.12",
     "Programming Language :: Python :: 3.13",
     "Topic :: Scientific/Engineering :: Hydrology"
 ]
-requires-python = ">=3.9"
+requires-python = ">=3.10"
 dynamic = ["version"]
 
 [project.optional-dependencies]