Drop python 3.9 support (#12120)

* Update `setup.py` to drop support for python 3.9

* Update github issue templates to not use python 3.9 as an example

* Update github workflows to no longer depend on or test python 3.9

* Drop python 3.9 from the test dockerfile

* Update `CONTRIBUTING.md` to correctly list what python versions we test

* Update comment about some code specifically needed for a python 3.9.7 issue

* Update pre-commit python version comment

* Add changie doc

* Update imports from click as upgrading to python 3.10 changed some click items

Author: QMalcolm

.changes/unreleased/Dependencies-20251027-162502.yaml

@@ -0,0 +1,6 @@
+kind: Dependencies
+body: Drop support for python 3.9
+time: 2025-10-27T16:25:02.435562-05:00
+custom:
+  Author: QMalcolm
+  Issue: "12118"

.github/ISSUE_TEMPLATE/bug-report.yml

@@ -62,7 +62,7 @@ body:
       description: |
         examples:
           - **OS**: Ubuntu 24.04
-          - **Python**: 3.9.12 (`python3 --version`)
+          - **Python**: 3.10.12 (`python3 --version`)
           - **dbt-core**: 1.1.1 (`dbt --version`)
       value: |
         - OS:

.github/ISSUE_TEMPLATE/regression-report.yml

@@ -56,7 +56,7 @@ body:
       description: |
         examples:
           - **OS**: Ubuntu 24.04
-          - **Python**: 3.9.12 (`python3 --version`)
+          - **Python**: 3.10.12 (`python3 --version`)
           - **dbt-core (working version)**: 1.1.1 (`dbt --version`)
           - **dbt-core (regression version)**: 1.2.0 (`dbt --version`)
       value: |

.github/workflows/main.yml

@@ -54,7 +54,7 @@ jobs:
       - name: Set up Python
         uses: actions/setup-python@v6
         with:
-          python-version: '3.9'
+          python-version: '3.10'
 
       - name: Install python dependencies
         run: |
@@ -77,7 +77,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python-version: [ "3.9", "3.10", "3.11", "3.12", "3.13" ]
+        python-version: ["3.10", "3.11", "3.12", "3.13" ]
 
     env:
       TOXENV: "unit"
@@ -142,7 +142,7 @@ jobs:
       - name: generate include
         id: generate-include
         run: |
-          INCLUDE=('"python-version":"3.9","os":"windows-latest"' '"python-version":"3.9","os":"macos-14"' )
+          INCLUDE=('"python-version":"3.10","os":"windows-latest"' '"python-version":"3.10","os":"macos-14"' )
           INCLUDE_GROUPS="["
           for include in ${INCLUDE[@]}; do
               for group in $(seq 1 ${{ env.PYTHON_INTEGRATION_TEST_WORKERS }}); do
@@ -164,7 +164,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python-version: [ "3.9", "3.10", "3.11", "3.12", "3.13" ]
+        python-version: [ "3.10", "3.11", "3.12", "3.13" ]
         os: ["ubuntu-latest"]
         split-group: ${{ fromJson(needs.integration-metadata.outputs.split-groups) }}
     env:
@@ -361,7 +361,7 @@ jobs:
       - name: Set up Python
         uses: actions/setup-python@v6
         with:
-          python-version: '3.9'
+          python-version: '3.10'
 
       - name: Install python dependencies
         run: |

.github/workflows/model_performance.yml

@@ -150,7 +150,7 @@ jobs:
       - name: Setup Python
         uses: actions/setup-python@v6
         with:
-          python-version: "3.9"
+          python-version: "3.10"
 
       - name: Install dbt
         run: pip install dbt-postgres==${{ needs.set-variables.outputs.release_id }}

.github/workflows/schema-check.yml

@@ -43,7 +43,7 @@ jobs:
       - name: Set up Python
         uses: actions/setup-python@v6
         with:
-          python-version: 3.9
+          python-version: "3.10"
 
       - name: Checkout dbt repo
         uses: actions/checkout@v4

.github/workflows/structured-logging-schema-check.yml

@@ -96,7 +96,7 @@ jobs:
       - name: Setup Python
         uses: actions/setup-python@v6
         with:
-          python-version: "3.9"
+          python-version: "3.10"
 
       - name: Install python dependencies
         run: |

.github/workflows/test-repeater.yml

@@ -27,7 +27,6 @@ on:
         description: 'Version of Python to Test Against'
         type: choice
         options:
-          - '3.9'
           - '3.10'
           - '3.11'
       os:

.pre-commit-config.yaml

@@ -3,7 +3,7 @@
 
 exclude: ^(core/dbt/docs/build/|core/dbt/common/events/types_pb2.py|core/dbt/adapters/events/adapter_types_pb2.py)
 
-# Force all unspecified python hooks to run python 3.9
+# Force all unspecified python hooks to run python 3.10
 default_language_version:
   python: python3
 

CONTRIBUTING.md

@@ -2,15 +2,34 @@
 
 `dbt-core` is open source software. It is what it is today because community members have opened issues, provided feedback, and [contributed to the knowledge loop](https://www.getdbt.com/dbt-labs/values/). Whether you are a seasoned open source contributor or a first-time committer, we welcome and encourage you to contribute code, documentation, ideas, or problem statements to this project.
 
-1. [About this document](#about-this-document)
-2. [Getting the code](#getting-the-code)
-3. [Setting up an environment](#setting-up-an-environment)
-4. [Running dbt-core in development](#running-dbt-core-in-development)
-5. [Testing dbt-core](#testing)
-6. [Debugging](#debugging)
-7. [Adding or modifying a changelog entry](#adding-or-modifying-a-changelog-entry)
-8. [Submitting a Pull Request](#submitting-a-pull-request)
-9. [Troubleshooting Tips](#troubleshooting-tips)
+- [Contributing to `dbt-core`](#contributing-to-dbt-core)
+  - [About this document](#about-this-document)
+    - [Notes](#notes)
+  - [Getting the code](#getting-the-code)
+    - [Installing git](#installing-git)
+    - [External contributors](#external-contributors)
+    - [dbt Labs contributors](#dbt-labs-contributors)
+  - [Setting up an environment](#setting-up-an-environment)
+    - [Tools](#tools)
+      - [Virtual environments](#virtual-environments)
+      - [Docker and `docker-compose`](#docker-and-docker-compose)
+      - [Postgres (optional)](#postgres-optional)
+  - [Running `dbt-core` in development](#running-dbt-core-in-development)
+    - [Installation](#installation)
+    - [Running `dbt-core`](#running-dbt-core)
+  - [Testing](#testing)
+    - [Initial setup](#initial-setup)
+    - [Test commands](#test-commands)
+      - [Makefile](#makefile)
+      - [`pre-commit`](#pre-commit)
+      - [`tox`](#tox)
+      - [`pytest`](#pytest)
+    - [Unit, Integration, Functional?](#unit-integration-functional)
+  - [Debugging](#debugging)
+    - [Assorted development tips](#assorted-development-tips)
+  - [Adding or modifying a CHANGELOG Entry](#adding-or-modifying-a-changelog-entry)
+  - [Submitting a Pull Request](#submitting-a-pull-request)
+  - [Troubleshooting Tips](#troubleshooting-tips)
 
 ## About this document
 
@@ -55,7 +74,7 @@ There are some tools that will be helpful to you in developing locally. While th
 
 These are the tools used in `dbt-core` development and testing:
 
-- [`tox`](https://tox.readthedocs.io/en/latest/) to manage virtualenvs across python versions. We currently target the latest patch releases for Python 3.8, 3.9, 3.10 and 3.11
+- [`tox`](https://tox.readthedocs.io/en/latest/) to manage virtualenvs across python versions. We currently target the latest patch releases for Python 3.10, 3.11, 3.12, and 3.13
 - [`pytest`](https://docs.pytest.org/en/latest/) to define, discover, and run tests
 - [`flake8`](https://flake8.pycqa.org/en/latest/) for code linting
 - [`black`](https://github.com/psf/black) for code formatting