Require Python 3.9

Re #2904

.github/workflows/test_runner.yml

@@ -17,7 +17,7 @@ jobs:
     strategy:
       fail-fast: true
       matrix:
-        python-version: [3.8, 3.9, "3.10", 3.11, 3.12]
+        python-version: ["3.9", "3.10", "3.11", "3.12"]
         os: [windows-latest, ubuntu-22.04]
     uses: ./.github/workflows/unit_tests.yml
     with:
@@ -29,7 +29,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python-version: [3.8, 3.9, "3.10", 3.11, 3.12]
+        python-version: ["3.9", "3.10", "3.11", "3.12"]
         os: [windows-latest, ubuntu-22.04]
     uses: ./.github/workflows/execution_tests.yml
     with:

CHANGELOG.md

@@ -5,6 +5,8 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.1.0/)
 
 ## [Unreleased]
 
+This version of Spine Toolbox requires Python version 3.9 or later.
+
 ### Added
 
 ### Changed

README.md

@@ -1,7 +1,7 @@
 # Spine Toolbox
 Link to the documentation: [https://spine-toolbox.readthedocs.io/en/latest/?badge=latest](https://spine-toolbox.readthedocs.io/en/latest/?badge=latest)
 
-[![Python](https://img.shields.io/badge/python-3.8%20|%203.9%20|%203.10%20|%203.11|%203.12-blue.svg)](https://www.python.org/downloads/release/python-379/)
+[![Python](https://img.shields.io/badge/python-3.9%20|%203.10%20|%203.11%20|%203.12-blue.svg)](https://www.python.org/downloads/release/python-379/)
 [![Documentation Status](https://readthedocs.org/projects/spine-toolbox/badge/?version=latest)](https://spine-toolbox.readthedocs.io/en/latest/?badge=latest)
 [![Test suite](https://github.com/spine-tools/Spine-Toolbox/actions/workflows/test_runner.yml/badge.svg)](https://github.com/spine-tools/Spine-Toolbox/actions/workflows/test_runner.yml)
 [![codecov](https://codecov.io/gh/spine-tools/Spine-Toolbox/branch/master/graph/badge.svg)](https://codecov.io/gh/spine-tools/Spine-Toolbox)
@@ -244,7 +244,7 @@ run it, and follow the instructions to install Spine Toolbox.
 
 ### About requirements
 
-Python 3.8.1 or later is required. Python 3.8.0 is not supported due to problems in DLL loading on Windows.
+Python 3.9 or later is required.
 
 See the files `pyproject.toml` and `requirements.txt` for packages required to run Spine Toolbox.
 (Additional packages needed for development are listed in `dev-requirements.txt`.)
@@ -277,7 +277,7 @@ also [Problems in starting the application](#problems-in-starting-the-applicatio
 
 #### Installation fails
 
-Please make sure you are using Python 3.8.1 or later to install the requirements.
+Please make sure you are using Python 3.9 or later to install the requirements.
 
 #### 'No Python' error when installing with pipx
 
@@ -317,8 +317,6 @@ The required `qtconsole` package from the ***conda-forge*** channel also
 installs `qt` and `PyQt` packages. Since this is a `PySide6` application, those 
 are not needed and there is a chance of conflicts between the packages.
 
-**Note**: Python 3.8.0 is not supported. Use Python 3.8.1 or later.
-
 ## Recorded Webinars showing the use of Spine Tools
 
 ### Spine Toolbox: Data, workflow and scenario management for modelling

pyproject.toml

@@ -11,7 +11,7 @@ classifiers = [
     "License :: OSI Approved :: GNU Lesser General Public License v3 (LGPLv3)",
     "Operating System :: OS Independent",
 ]
-requires-python = ">=3.8.1"
+requires-python = ">=3.9, <3.13"
 dependencies = [
     "PySide6 >= 6.5.0, != 6.5.3, != 6.6.3, != 6.7.0, < 6.8",
     "jupyter_client >=6.0",

spinetoolbox/main.py

@@ -47,7 +47,6 @@ def main():
     )
     if not pyside6_version_check():
         return 1
-    _add_pywin32_system32_to_path()
     parser = _make_argument_parser()
     args = parser.parse_args()
     if args.execute_only or args.list_items or args.execute_remotely:
@@ -98,14 +97,3 @@ def _make_argument_parser():
     )
     parser.add_argument("--execute-remotely", help="execute remotely", action="append", metavar="SERVER CONFIG FILE")
     return parser
-
-
-def _add_pywin32_system32_to_path():
-    """Adds a directory to PATH on Windows that is required to make pywin32 work
-    on (Conda) Python 3.8. See https://github.com/spine-tools/Spine-Toolbox/issues/1230."""
-    if sys.platform != "win32":
-        return
-    if sys.version_info[0:2] == (3, 8):
-        p = os.path.join(sys.exec_prefix, "Lib", "site-packages", "pywin32_system32")
-        if os.path.exists(p):
-            os.environ["PATH"] = p + ";" + os.environ["PATH"]

spinetoolbox/ui_main.py

@@ -441,7 +441,7 @@ def init_tasks(self, project_dir_from_args):
         """
         self._display_welcome_message()
         if sys.version_info < (3, 9):
-            self._display_python_38_deprecation_message()
+            self._display_deprecated_python_warning()
         self.init_project(project_dir_from_args)
 
     def _display_welcome_message(self):
@@ -455,12 +455,11 @@ def _display_welcome_message(self):
         welcome_msg = f"Welcome to Spine Toolbox! If you need help, please read the {getting_started_anchor} guide."
         self.msg.emit(welcome_msg)
 
-    def _display_python_38_deprecation_message(self):
-        """Shows Python 3.8 deprecation message in the event log."""
+    def _display_deprecated_python_warning(self):
+        """Shows a warning message in Event log."""
         self.msg_warning.emit("Please upgrade your Python.")
         self.msg_warning.emit(
-            f"Looks like you are running Python {sys.version_info[0]}.{sys.version_info[1]}. "
-            f"Support for <b>Python older than 3.9 </b> will be dropped in September 2024."
+            f"Your Python version {sys.version_info[0]}.{sys.version_info[1]} is unsupported. Expect trouble."
         )
 
     def init_project(self, project_dir):