feat!: drop python 3.9 and 3.10, require >=3.11

BREAKING CHANGE: python 3.9 and 3.10 are no longer supported, and the
PySide2 backend is dropped along with them (PySide2 5.15.2.1 declares
`requires_python <3.11` and ships no wheel past cp310, so it cannot be
installed or tested on the new floor).

- requires-python = ">=3.11"; drop the 3.9/3.10 classifiers
- drop the pyside2 extra, dependency-group, docs and CI jobs, along with
  the test-qt-legacy group and [tool.uv] conflicts block that existed
  only to keep PySide2 on pytest-qt 4.4
- CI: base matrix 3.10 -> 3.11, min-deps 3.9 -> 3.11, pyqt5 job 3.9 ->
  3.11, test-dependents default 3.10 -> 3.11
- SLOTS is now unconditional, and the <3.11 weakref_slot skip is dead
- ruff target-version py39 -> py311, and pin the dev ruff/mypy to the
  versions pre-commit already runs (they had drifted to ruff 0.15.12
  against pre-commit's 0.16.4)

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

Author: tlambert03

.github/workflows/test_and_deploy.yml

@@ -23,26 +23,20 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python-version: ["3.10", "3.13"]
+        python-version: ["3.11", "3.13"]
         os: [ubuntu-latest, macos-latest, windows-latest]
         add-group: [pyqt6, pyside6]
         include:
           - os: windows-latest
             python-version: "3.11"
             resolution: "lowest-direct"
             add-group: pyside6
-          - python-version: "3.9"
+          - python-version: "3.11"
             os: ubuntu-latest
             add-group: pyqt5
-          - python-version: "3.9"
-            os: ubuntu-latest
-            add-group: pyside2
           - python-version: "3.12"
             os: windows-latest
             add-group: pyqt5
-          - python-version: "3.10"
-            os: windows-latest
-            add-group: pyside2
           - python-version: "3.12"
             os: ubuntu-latest
             add-group: pyqt6
@@ -109,7 +103,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python-version: ["3.9", "3.13"]
+        python-version: ["3.11", "3.13"]
         os: [macos-latest]
 
     steps:
@@ -148,7 +142,7 @@ jobs:
       dependency-extras: ${{ matrix.package-extras || '' }}
       dependency-group: ${{ matrix.package-group || '' }}
       qt: pyqt5
-      python-version: ${{ matrix.python-version || '3.10' }}
+      python-version: ${{ matrix.python-version || '3.11' }}
       post-install-cmd: "python -m pip install pytest-pretty lxml_html_clean" # just for napari
       pytest-args: ${{ matrix.pytest-args }}
     strategy:

README.md

@@ -39,21 +39,21 @@
 
 ## Installation
 
-`magicgui` uses `qtpy` to support both `pyside2` and `pyqt5` backends.  However, you
+`magicgui` uses `qtpy` to support both `pyqt` and `pyside` backends.  However, you
 must have one of those installed for magicgui to work.
 
 install with pip
 
 ```bash
-pip install magicgui[pyqt5]
+pip install magicgui[pyqt6]
 # or
-pip install magicgui[pyside2]
+pip install magicgui[pyside6]
 ```
 
 or with conda:
 
 ```bash
-conda install -c conda-forge magicgui pyqt  # or pyside2 instead of pyqt
+conda install -c conda-forge magicgui pyqt  # or pyside6 instead of pyqt
 ```
 
 > :information_source: If you'd like to help us extend support to a different backend,

docs/index.md

@@ -160,8 +160,7 @@ environments (such as a desktop app, or a Jupyter notebook).
 Currently, **magicgui** supports the following backends:
 
 - [Qt](https://www.qt.io/) (via
-  [PySide2](https://pypi.org/project/PySide2/)/[PySide6](https://pypi.org/project/PySide6/)
-  or
+  [PySide6](https://pypi.org/project/PySide6/) or
   [PyQt5](https://pypi.org/project/PyQt5/)/[PyQt6](https://pypi.org/project/PyQt6/))
 - [Jupyter Widgets](https://ipywidgets.readthedocs.io/en/latest/) (a.k.a.
   "IPyWidgets")

docs/installation.md

@@ -20,7 +20,6 @@ available:
 
 - `PyQt5`:  `pip install magicgui[pyqt5]`
 - `PyQt6`:  `pip install magicgui[pyqt6]`
-- `PySide2`:  `pip install magicgui[pyside2]`
 - `PySide6`:  `pip install magicgui[pyside6]`
 - `Jupyter Widgets`:  `pip install magicgui[jupyter]`
 

pyproject.toml

@@ -20,7 +20,7 @@ name = "magicgui"
 description = " build GUIs from python types"
 keywords = ["gui", "widgets", "type annotations"]
 readme = "README.md"
-requires-python = ">=3.9"
+requires-python = ">=3.11"
 license = { text = "MIT" }
 authors = [{ email = "talley.lambert@gmail.com", name = "Talley Lambert" }]
 classifiers = [
@@ -32,8 +32,6 @@ classifiers = [
     "Operating System :: OS Independent",
     "Programming Language :: Python",
     "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",
     "Programming Language :: Python :: 3.13",
@@ -63,7 +61,6 @@ pyqt5 = [
     "pyqt5-qt5>5.15.2; sys_platform != 'win32'",
 ]
 pyqt6 = ["pyqt6>=6.4.0"]
-pyside2 = ["pyside2>=5.15"]
 pyside6 = ["pyside6>=6.4.0"]
 tqdm = ["tqdm>=4.30.0"]
 jupyter = ["ipywidgets>=8.0.0"]
@@ -78,31 +75,27 @@ third-party-support = [
     "matplotlib>=3.9.4",
     "numpy>=2.1.0; python_version >= '3.13'",
     "numpy>=1.26.4",
-    "pandas>=2.2.3; python_version >= '3.11'",
-    "pandas>=2.1",
+    "pandas>=2.2.3",
     "pydantic>=1.10.18",
     "toolz>=1.0.0",
 ]
 test-min = ["pytest>=8.4.0", "pytest-cov >=6.1", "pytest-mypy-plugins>=3.1"]
 # pytest-qt >=4.5 fixes SystemError/TimeoutError in qtbot.waitSignal with
-# recent PySide6 (pytest-dev/pytest-qt#552), but drops PySide2 support --
-# so the pyside2 group uses the legacy pin (see [tool.uv] conflicts below)
+# recent PySide6 (pytest-dev/pytest-qt#552)
 test-qt = [{ include-group = "test-min" }, "pytest-qt>=4.5.0"]
-test-qt-legacy = [{ include-group = "test-min" }, "pytest-qt==4.4.0"]
 test = [
     "magicgui[tqdm,jupyter,image,quantity]",
     { include-group = "test-min" },
     { include-group = "third-party-support" },
 ]
 pyqt5 = ["magicgui[pyqt5]", { include-group = "test-qt" }]
 pyqt6 = ["magicgui[pyqt6]", { include-group = "test-qt" }]
-pyside2 = ["magicgui[pyside2]", { include-group = "test-qt-legacy" }, "numpy<2; python_version < '3.13'"]
 pyside6 = ["magicgui[pyside6]", { include-group = "test-qt" }]
 dev = [
     { include-group = "test" },
-    "ruff>=0.8.3",
+    "ruff>=0.16.4",
     "ipython>=8.18.0",
-    "mypy>=1.13.0",
+    "mypy>=2.3.1",
     "pdbpp>=0.11.6; sys_platform != 'win32'",
     "pre-commit-uv>=4",
     "pyqt6>=6.8.0",
@@ -129,10 +122,6 @@ docs = [
     "ipykernel>=6.29.5",
 ]
 
-[tool.uv]
-# the two pytest-qt pins are mutually exclusive; no environment installs both
-conflicts = [[{ group = "test-qt" }, { group = "test-qt-legacy" }]]
-
 [tool.uv.sources]
 magicgui = { workspace = true }
 
@@ -148,7 +137,7 @@ documentation = "https://pyapp-kit.github.io/magicgui/"
 # https://docs.astral.sh/ruff
 [tool.ruff]
 line-length = 88
-target-version = "py39"
+target-version = "py311"
 src = ["src", "tests"]
 fix = true
 unsafe-fixes = true
@@ -172,8 +161,20 @@ select = [
 ]
 ignore = [
     "D401", # First line should be in imperative mood
+    # magicgui resolves annotations at *runtime*, and on python < 3.14
+    # `get_origin(int | None)` is `types.UnionType`, not `typing.Union` -- so
+    # rewriting Optional/Union to PEP 604 changes behaviour rather than just
+    # spelling. Tests also deliberately exercise both spellings.
+    "UP007", # Use `X | Y` for type annotations
+    "UP045", # Use `X | None` for type annotations
 ]
 
+[tool.ruff.lint.flake8-type-checking]
+# ruff exempts `typing`/`typing_extensions` by default; `collections.abc` now
+# supplies Callable etc. after the pyupgrade rewrite, and magicgui resolves
+# annotations at runtime -- so these names must stay importable at runtime.
+exempt-modules = ["typing", "typing_extensions", "collections.abc"]
+
 [tool.ruff.lint.per-file-ignores]
 "tests/*.py" = ["D", "S", "E501"]
 "tests/test_util.py" = ["D", "S", "E501", "UP006"]

src/magicgui/_type_resolution.py

@@ -1,9 +1,10 @@
 import types
 import typing
+from collections.abc import Callable
 from copy import copy
 from functools import lru_cache, partial
 from importlib import import_module
-from typing import Any, Callable, Optional, Union, get_type_hints
+from typing import Any, Optional, Union, get_type_hints
 
 try:
     from toolz import curry

src/magicgui/_util.py

@@ -4,11 +4,11 @@
 import os
 import sys
 import time
+from collections.abc import Callable
 from functools import wraps
 from pathlib import Path
 from typing import (
     TYPE_CHECKING,
-    Callable,
     get_args,
     get_origin,
     overload,
@@ -177,7 +177,8 @@ def _safe_isinstance_tuple(obj: object, superclass: object) -> bool:
             return all(safe_issubclass(o, superclass_args[0]) for o in obj_args)
         # fallback to simple compare
         return len(obj_args) == len(superclass_args) and all(
-            safe_issubclass(o, s) for o, s in zip(obj_args, superclass_args)
+            safe_issubclass(o, s)
+            for o, s in zip(obj_args, superclass_args, strict=False)
         )
 
     if len(obj_args) == 2 and obj_args[1] is Ellipsis:
@@ -215,7 +216,10 @@ def safe_issubclass(obj: object, superclass: object) -> bool:
             return True
         if len(obj_args) != len(superclass_args):
             return False
-        return all(safe_issubclass(o, s) for o, s in zip(obj_args, superclass_args))
+        return all(
+            safe_issubclass(o, s)
+            for o, s in zip(obj_args, superclass_args, strict=False)
+        )
 
     except Exception:
         return False

src/magicgui/application.py

@@ -3,9 +3,10 @@
 from __future__ import annotations
 
 import signal
+from collections.abc import Callable
 from contextlib import contextmanager
 from importlib import import_module
-from typing import TYPE_CHECKING, Any, Callable, Union
+from typing import TYPE_CHECKING, Any, Union
 
 from magicgui.backends import BACKENDS
 

src/magicgui/backends/_ipynb/widgets.py

@@ -1,6 +1,7 @@
 from __future__ import annotations
 
-from typing import TYPE_CHECKING, Any, Callable, get_type_hints
+from collections.abc import Callable
+from typing import TYPE_CHECKING, Any, get_type_hints
 
 try:
     import ipywidgets

src/magicgui/backends/_qtpy/widgets.py

@@ -5,10 +5,11 @@
 import math
 import re
 import warnings
+from collections.abc import Callable
 from contextlib import contextmanager, suppress
 from functools import partial
 from itertools import chain
-from typing import TYPE_CHECKING, Any, Callable
+from typing import TYPE_CHECKING, Any
 
 import qtpy
 import superqt