refactor(python): drop Python 3.9 support, require Python 3.10+

BREAKING CHANGE: Python 3.9 is EOL and no longer supported.

- Update requires-python to >=3.10 in pyproject.toml
- Remove Python 3.9 classifier and 3.9-only matplotlib dependency
- Set ruff target-version to py310
- Update CI matrix minimum version from 3.9 to 3.10 (pytest, pylint, pyright workflows)
- Modernize 512 typing annotations: Optional[X]→X|None, Union[X,Y]→X|Y
- Remove redundant Optional/Union imports from typing module
- Update test asserting UnionType origin to use types.UnionType instead of typing.Unionfix tests

Author: amilcarlucas

.github/workflows/pylint.yml

@@ -23,7 +23,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: ["3.9", "3.14"]
+        python-version: ["3.10", "3.14"]
 
     steps:
     - name: Harden the runner (Audit all outbound calls)

.github/workflows/pyright.yml

@@ -23,7 +23,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
         matrix:
-          python-version: ["3.9", "3.14"]
+          python-version: ["3.10", "3.14"]
 
     steps:
       - name: Harden the runner (Audit all outbound calls)

.github/workflows/pytest.yml

@@ -31,7 +31,7 @@ jobs:
         python-version: ["3.14"]  # to make sure the latest AMC supported python version does not break
         include:
           - os: ubuntu-latest
-            python-version: "3.9"  # to make sure the minimum AMC supported python version does not break
+            python-version: "3.10"  # to make sure the minimum AMC supported python version does not break
             # this is also the version used to report test coverage, other versions do not report coverage
 
     steps:
@@ -269,7 +269,7 @@ jobs:
         with:
           github-token: ${{ secrets.GITHUB_TOKEN }}
           parallel-finished: true
-          carryforward: "run-ubuntu-latest-py3.9,run-ubuntu-latest-py3.14,run-windows-latest-py3.14,run-macos-latest-py3.14"
+          carryforward: "run-ubuntu-latest-py3.10,run-ubuntu-latest-py3.14,run-windows-latest-py3.14,run-macos-latest-py3.14"
 
       # TODO: create a badge that presents the result of the Upload coverage xml report step
 
@@ -345,14 +345,14 @@ jobs:
         if: needs.pytest.result != 'skipped'
         uses: actions/download-artifact@3e5f45b2cfb9172054b4087a40e8e0b5a5461e7c # v8.0.1
         with:
-          name: coverage-ubuntu-latest-3.9
+          name: coverage-ubuntu-latest-3.10
 
       # https://docs.astral.sh/uv/guides/integration/github/
       - name: Install uv and set the Python version
         if: needs.pytest.result != 'skipped'
         uses: astral-sh/setup-uv@08807647e7069bb48b6ef5acd8ec9567f424441b # v8.1.0
         with:
-          python-version: '3.9'  # Match with the coverage report Python version
+          python-version: '3.10'  # Match with the coverage report Python version
           activate-environment: true
           enable-cache: true
           cache-dependency-glob: "pyproject.toml"
@@ -389,7 +389,7 @@ jobs:
       - name: Download coverage xml report
         uses: actions/download-artifact@3e5f45b2cfb9172054b4087a40e8e0b5a5461e7c # v8.0.1
         with:
-          name: coverage-ubuntu-latest-3.9-xml
+          name: coverage-ubuntu-latest-3.10-xml
 
       - name: Get Cover
         uses: orgoro/coverage@71cf993a407154ad9d8dd027c88a374b0ed002a9 # v3.3

ardupilot_methodic_configurator/__main__.py

@@ -29,7 +29,6 @@
 from logging import warning as logging_warning
 from pathlib import Path
 from sys import exit as sys_exit
-from typing import Union
 
 import argcomplete
 
@@ -117,7 +116,7 @@ def __init__(self, args: argparse.Namespace) -> None:
         self.vehicle_type: str = ""
         self.param_default_values: ParDict = ParDict()
         self.local_filesystem: LocalFilesystem = None  # type: ignore[assignment]
-        self.vehicle_project_manager: Union[VehicleProjectManager, None] = None
+        self.vehicle_project_manager: VehicleProjectManager | None = None
         self.param_default_values_dirty: bool = False
 
 
@@ -391,7 +390,7 @@ def initialize_flight_controller_and_filesystem(state: ApplicationState) -> None
     initialize_filesystem(state)
 
 
-def vehicle_directory_selection(state: ApplicationState) -> Union[VehicleProjectOpenerWindow, None]:
+def vehicle_directory_selection(state: ApplicationState) -> VehicleProjectOpenerWindow | None:
     """
     Handle vehicle directory selection if no parameter files are found in the current working directory.
 
@@ -434,7 +433,7 @@ def create_and_configure_component_editor(
     local_filesystem: LocalFilesystem,
     flight_controller: FlightController,
     vehicle_type: str,
-    vehicle_project_manager: Union[None, VehicleProjectManager],
+    vehicle_project_manager: None | VehicleProjectManager,
 ) -> ComponentEditorWindow:
     """
     Create and configure the component editor window.

ardupilot_methodic_configurator/annotate_params.py

@@ -30,7 +30,7 @@
 import re
 from os import path as os_path
 from sys import exit as sys_exit
-from typing import Any, Optional
+from typing import Any
 from xml.etree import ElementTree as ET  # no parsing, just data-structure manipulation
 
 import argcomplete
@@ -139,7 +139,7 @@ def check_max_line_length(value: int) -> int:
 
 
 def get_xml_data(
-    base_url: str, directory: str, filename: str, vehicle_type: str, fallback_xml_url: Optional[str] = None
+    base_url: str, directory: str, filename: str, vehicle_type: str, fallback_xml_url: str | None = None
 ) -> ET.Element:
     """
     Fetch XML data from a local file or a URL.
@@ -418,7 +418,7 @@ def update_parameter_documentation(
     doc: dict[str, Any],
     target: str = ".",
     sort_type: str = "none",
-    param_default_dict: Optional[ParDict] = None,
+    param_default_dict: ParDict | None = None,
     delete_documentation_annotations: bool = False,
 ) -> None:
     """
@@ -595,7 +595,7 @@ def get_fallback_xml_url(vehicle_type: str, firmware_version: str) -> str:
 
 
 def parse_parameter_metadata(  # pylint: disable=too-many-arguments, too-many-positional-arguments
-    xml_url: str, xml_dir: str, xml_file: str, vehicle_type: str, max_line_length: int, fallback_xml_url: Optional[str] = None
+    xml_url: str, xml_dir: str, xml_file: str, vehicle_type: str, max_line_length: int, fallback_xml_url: str | None = None
 ) -> dict[str, Any]:
     xml_root = get_xml_data(xml_url, xml_dir, xml_file, vehicle_type, fallback_xml_url)
     return create_doc_dict(xml_root, vehicle_type, max_line_length)

ardupilot_methodic_configurator/argparse_check_range.py

@@ -13,7 +13,7 @@
 from argparse import Action, ArgumentError, ArgumentParser, Namespace
 from collections.abc import Sequence
 from operator import ge, gt, le, lt
-from typing import Any, Union
+from typing import Any
 
 from ardupilot_methodic_configurator import _
 
@@ -56,8 +56,8 @@ def __call__(
         self,
         parser: ArgumentParser,  # noqa: ARG002
         namespace: Namespace,
-        values: Union[str, Sequence[Any], None],
-        option_string: Union[None, str] = None,  # noqa: ARG002
+        values: str | Sequence[Any] | None,
+        option_string: None | str = None,  # noqa: ARG002
     ) -> None:
         if not isinstance(values, (int, float)):
             raise ArgumentError(self, _("Value must be a number."))

ardupilot_methodic_configurator/backend_filesystem.py

@@ -30,7 +30,7 @@
 from shutil import copytree as shutil_copytree
 from shutil import rmtree as shutil_rmtree
 from subprocess import SubprocessError, run
-from typing import Any, Optional, Union
+from typing import Any
 from zipfile import ZipFile
 
 from argcomplete.completers import DirectoriesCompleter
@@ -201,7 +201,7 @@ def _format_columns_sorted_numerically(  # pylint: disable=too-many-locals
             return []
 
         # Sort values numerically by key
-        def sort_key(item: tuple[str, Any]) -> tuple[int, Union[int, float, str]]:
+        def sort_key(item: tuple[str, Any]) -> tuple[int, int | float | str]:
             key = item[0]
             try:
                 return (0, int(key))  # sort integers and floats together
@@ -358,7 +358,7 @@ def read_params_from_files(self) -> dict[str, ParDict]:
             logging_error(_("Error: %s is not a directory."), self.vehicle_dir)
         return parameters
 
-    def compound_params(self, last_filename: Optional[str] = None, skip_default: bool = True) -> tuple[ParDict, Optional[str]]:
+    def compound_params(self, last_filename: str | None = None, skip_default: bool = True) -> tuple[ParDict, str | None]:
         """
         Compound parameters from multiple .param files into a single ParDict.
 
@@ -399,7 +399,7 @@ def compound_params(self, last_filename: Optional[str] = None, skip_default: boo
         return compound, first_config_step_filename
 
     @staticmethod
-    def str_to_bool(s: str) -> Optional[bool]:
+    def str_to_bool(s: str) -> bool | None:
         """
         Converts a string representation of a boolean value to a boolean.
 
@@ -606,7 +606,7 @@ def copy_template_files_to_new_vehicle_dir(  # pylint: disable=too-many-argument
         blank_change_reason: bool,
         copy_vehicle_image: bool,
         use_fc_params: bool = False,
-        fc_parameters: Optional[dict[str, float]] = None,
+        fc_parameters: dict[str, float] | None = None,
     ) -> str:
         # Copy the template files to the new vehicle directory
         try:
@@ -662,7 +662,7 @@ def _transform_param_dict(
         params: ParDict,
         blank_change_reason: bool,
         use_fc_params: bool,
-        fc_parameters: Optional[dict[str, float]],
+        fc_parameters: dict[str, float] | None,
     ) -> None:
         """
         Apply in-place transformations to a parameter dict during template copy.
@@ -845,7 +845,7 @@ def get_eval_variables(self) -> dict[str, dict[str, Any]]:
     def calculate_derived_and_forced_param_changes(
         self,
         fc_param_names: list[str],
-        fc_parameters: Optional[dict[str, float]] = None,
+        fc_parameters: dict[str, float] | None = None,
     ) -> dict[str, ParDict]:
         """
         Compute updated parameter values for all configuration files.
@@ -966,8 +966,8 @@ def merge_forced_or_derived_parameters(
         self,
         filename: str,
         new_parameters: dict[str, ParDict],
-        fc_param_names: Optional[list[str]],
-        target: Optional[ParDict] = None,
+        fc_param_names: list[str] | None,
+        target: ParDict | None = None,
     ) -> bool:
         """
         Merge forced or derived parameter values into a target parameter dict.

ardupilot_methodic_configurator/backend_filesystem_configuration_steps.py

@@ -16,7 +16,7 @@
 from math import isfinite
 from os import path as os_path
 from re import search as re_search
-from typing import Any, Optional, TypedDict, Union
+from typing import Any, TypedDict
 
 # from sys import exit as sys_exit
 from jsonschema import validate as json_validate
@@ -290,7 +290,7 @@ def _ensure_file_entry(destination: dict[str, ParDict], filename: str) -> None:
 
     def _eval_new_value(  # pylint: disable=too-many-arguments, too-many-positional-arguments
         self,
-        new_value_expr: Union[str, float, bool],
+        new_value_expr: str | float | bool,
         filename: str,
         parameter: str,
         parameter_type: str,
@@ -618,7 +618,7 @@ def get_sorted_phases_with_end_and_weight(self, total_files: int) -> dict[str, P
 
         return sorted_phases
 
-    def get_plugin(self, selected_file: str) -> Optional[dict]:
+    def get_plugin(self, selected_file: str) -> dict | None:
         """
         Get the plugin configuration for the selected file.
 
@@ -633,7 +633,7 @@ def get_plugin(self, selected_file: str) -> Optional[dict]:
             return self.configuration_steps[selected_file].get("plugin")
         return None
 
-    def get_instructions_popup(self, selected_file: str) -> Optional[dict]:
+    def get_instructions_popup(self, selected_file: str) -> dict | None:
         """Get the instructions popup configuration for the selected file."""
         if selected_file in self.configuration_steps:
             return self.configuration_steps[selected_file].get("instructions_popup")

ardupilot_methodic_configurator/backend_filesystem_freedesktop.py

@@ -24,7 +24,6 @@
 from os import path as os_path
 from shutil import which as shutil_which
 from sys import platform as sys_platform
-from typing import Optional, Union
 
 from ardupilot_methodic_configurator.backend_filesystem_program_settings import ProgramSettings
 
@@ -57,7 +56,7 @@ def _desktop_icon_exists(desktop_file_path: str) -> bool:
         return os_path.exists(desktop_file_path)
 
     @staticmethod
-    def _get_virtual_env_path() -> Optional[str]:
+    def _get_virtual_env_path() -> str | None:
         """Get the virtual environment path from environment variables."""
         return os_environ.get("VIRTUAL_ENV")
 
@@ -157,7 +156,7 @@ def create_desktop_icon_if_needed() -> None:
             logging_error("Failed to create application launch desktop icon")
 
     @staticmethod
-    def _get_desktop_startup_id() -> Union[str, None]:
+    def _get_desktop_startup_id() -> str | None:
         """
         Get the DESKTOP_STARTUP_ID environment variable.
 

ardupilot_methodic_configurator/backend_filesystem_json_with_schema.py

@@ -17,7 +17,7 @@
 from logging import debug as logging_debug
 from logging import error as logging_error
 from os import path as os_path
-from typing import Any, Union
+from typing import Any
 
 from jsonschema import ValidationError, validate, validators
 
@@ -31,8 +31,8 @@ class FilesystemJSONWithSchema:
     def __init__(self, json_filename: str, schema_filename: str) -> None:
         self.json_filename = json_filename
         self.schema_filename = schema_filename
-        self.data: Union[None, dict[str, Any]] = None
-        self.schema: Union[None, dict[Any, Any]] = None
+        self.data: None | dict[str, Any] = None
+        self.schema: None | dict[Any, Any] = None
 
     def load_schema(self) -> dict:
         """