Drop support for Python 3.9

.github/workflows/build_lint.yml

@@ -36,8 +36,6 @@ jobs:
             python-version: "3.11"
           - os: ubuntu
             python-version: "3.10"
-          - os: ubuntu
-            python-version: "3.9"
           # Disabled for now. See https://github.com/projectmesa/mesa/issues/1253
           #- os: ubuntu
           #  python-version: 'pypy-3.8'

docs/tutorials/intro_tutorial.ipynb

@@ -60,7 +60,7 @@
    "source": [
     "### Tutorial Setup\n",
     "\n",
-    "Create and activate a [virtual environment](http://docs.python-guide.org/en/latest/dev/virtualenvs/). *Python version 3.9 or higher is required*.\n",
+    "Create and activate a [virtual environment](http://docs.python-guide.org/en/latest/dev/virtualenvs/). *Python version 3.10 or higher is required*.\n",
     "\n",
     "Install Mesa:\n",
     "\n",

mesa/agent.py

@@ -13,11 +13,11 @@
 import warnings
 import weakref
 from collections import defaultdict
-from collections.abc import Iterable, Iterator, MutableSet, Sequence
+from collections.abc import Callable, Iterable, Iterator, MutableSet, Sequence
 from random import Random
 
 # mypy
-from typing import TYPE_CHECKING, Any, Callable
+from typing import TYPE_CHECKING, Any
 
 if TYPE_CHECKING:
     # We ensure that these are not imported during runtime to prevent cyclic

mesa/space.py

@@ -23,9 +23,9 @@
 import itertools
 import math
 import warnings
-from collections.abc import Iterable, Iterator, Sequence
+from collections.abc import Callable, Iterable, Iterator, Sequence
 from numbers import Real
-from typing import Any, Callable, TypeVar, Union, cast, overload
+from typing import Any, TypeVar, Union, cast, overload
 from warnings import warn
 
 with contextlib.suppress(ImportError):

pyproject.toml

@@ -6,7 +6,7 @@ build-backend = "hatchling.build"
 name = "Mesa"
 description = "Agent-based modeling (ABM) in Python"
 license = { text = "Apache 2.0" }
-requires-python = ">=3.9"
+requires-python = ">=3.10"
 authors = [
   { name = "Project Mesa Team", email = "[email protected]" },
 ]
@@ -25,7 +25,6 @@ classifiers = [
   "Topic :: Scientific/Engineering :: Artificial Intelligence",
   "Intended Audience :: Science/Research",
   "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",
@@ -127,6 +126,6 @@ extend-ignore = [
     "ISC001",  # ruff format asks to disable this feature
 ]
 extend-exclude = ["docs", "build"]
-# Hardcode to Python 3.9.
+# Hardcode to Python 3.10.
 # Reminder to update mesa-examples if the value below is changed.
-target-version = "py39"
+target-version = "py310"