[Backport 1.6.latest] Drop support for Python 3.8 (#1219)

* backport #1211

.changes/unreleased/Breaking Changes-20241016-183143.yaml

@@ -0,0 +1,6 @@
+kind: Breaking Changes
+body: Drop support for Python 3.8
+time: 2024-10-16T18:31:43.4167-04:00
+custom:
+  Author: mikealfare
+  Issue: "1211"

.github/scripts/integration-test-matrix.js

@@ -1,6 +1,6 @@
 module.exports = ({ context }) => {
-  const defaultPythonVersion = "3.8";
-  const supportedPythonVersions = ["3.8", "3.9", "3.10", "3.11"];
+  const defaultPythonVersion = "3.9";
+  const supportedPythonVersions = ["3.9", "3.10", "3.11"];
   const supportedAdapters = ["snowflake"];
 
   // if PR, generate matrix based on files changed and PR labels

.github/workflows/main.yml

@@ -50,7 +50,7 @@ jobs:
       - name: Set up Python
         uses: actions/setup-python@v4
         with:
-          python-version: '3.8'
+          python-version: '3.9'
 
       - name: Install python dependencies
         run: |
@@ -72,7 +72,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python-version: ['3.8', '3.9', '3.10', '3.11']
+        python-version: ['3.9', '3.10', '3.11']
 
     env:
       TOXENV: "unit"
@@ -127,7 +127,7 @@ jobs:
       - name: Set up Python
         uses: actions/setup-python@v4
         with:
-          python-version: '3.8'
+          python-version: '3.9'
 
       - name: Install python dependencies
         run: |
@@ -174,7 +174,7 @@ jobs:
       fail-fast: false
       matrix:
         os: [ubuntu-latest, macos-12, windows-latest]
-        python-version: ['3.8', '3.9', '3.10', '3.11']
+        python-version: ['3.9', '3.10', '3.11']
 
     steps:
       - name: Set up Python ${{ matrix.python-version }}

.pre-commit-config.yaml

@@ -21,14 +21,14 @@ repos:
     additional_dependencies: ['click~=8.1']
     args:
     - "--line-length=99"
-    - "--target-version=py38"
+    - "--target-version=py39"
   - id: black
     alias: black-check
     stages: [manual]
     additional_dependencies: ['click~=8.1']
     args:
     - "--line-length=99"
-    - "--target-version=py38"
+    - "--target-version=py39"
     - "--check"
     - "--diff"
 - repo: https://github.com/pycqa/flake8

CONTRIBUTING.md

@@ -79,7 +79,7 @@ WARNING: The parameters in your `test.env` file must link to a valid Snowflake a
 There are a few methods for running tests locally.
 
 #### `tox`
-`tox` automatically runs unit tests against several Python versions using its own virtualenvs. Run `tox -p` to run unit tests for Python 3.8, Python 3.9, Python 3.10, and `flake8` in parallel. Run `tox -e py38` to invoke tests on Python version 3.8 only (use py38, py39, or py310). Tox recipes are found in `tox.ini`.
+`tox` automatically runs unit tests against several Python versions using its own virtualenvs. Run `tox -p` to run unit tests for Python 3.9 and Python 3.10, and `flake8` in parallel. Run `tox -e py39` to invoke tests on Python version 3.9 only (use py39 or py310). Tox recipes are found in `tox.ini`.
 
 #### `pytest`
 You may run a specific test or group of tests using `pytest` directly. Activate a Python virtualenv active with dev dependencies installed. Then, run tests like so:

Makefile

@@ -38,22 +38,22 @@ linecheck: ## Checks for all Python lines 100 characters or more
 	find dbt -type f -name "*.py" -exec grep -I -r -n '.\{100\}' {} \;
 
 .PHONY: unit
-unit: ## Runs unit tests with py38.
+unit: ## Runs unit tests with py39.
 	@\
-	tox -e py38
+	tox -e py39
 
 .PHONY: test
-test: ## Runs unit tests with py38 and code checks against staged changes.
+test: ## Runs unit tests with py39 and code checks against staged changes.
 	@\
-	tox -p -e py38; \
+	tox -p -e py39; \
 	pre-commit run black-check --hook-stage manual | grep -v "INFO"; \
 	pre-commit run flake8-check --hook-stage manual | grep -v "INFO"; \
 	pre-commit run mypy-check --hook-stage manual | grep -v "INFO"
 
 .PHONY: integration
-integration: ## Runs snowflake integration tests with py38.
+integration: ## Runs snowflake integration tests with py39.
 	@\
-	tox -e py38-snowflake --
+	tox -e py39-snowflake --
 
 .PHONY: clean
 	@echo "cleaning repo"

setup.py

@@ -4,9 +4,9 @@
 import re
 
 # require python 3.8 or newer
-if sys.version_info < (3, 8):
+if sys.version_info < (3, 9):
     print("Error: dbt does not support this version of Python.")
-    print("Please upgrade to Python 3.8 or higher.")
+    print("Please upgrade to Python 3.9 or higher.")
     sys.exit(1)
 
 
@@ -79,11 +79,9 @@ def _get_dbt_core_version():
         "Operating System :: Microsoft :: Windows",
         "Operating System :: MacOS :: MacOS X",
         "Operating System :: POSIX :: Linux",
-        "Programming Language :: Python :: 3.8",
-        "Programming Language :: Python :: 3.8",
         "Programming Language :: Python :: 3.9",
         "Programming Language :: Python :: 3.10",
         "Programming Language :: Python :: 3.11",
     ],
-    python_requires=">=3.8",
+    python_requires=">=3.9",
 )

tox.ini

@@ -1,8 +1,8 @@
 [tox]
 skipsdist = True
-envlist = py38,py39,py310,py311
+envlist = py39,py310,py311
 
-[testenv:{unit,py38,py39,py310,py311,py}]
+[testenv:{unit,py39,py310,py311,py}]
 description = unit testing
 skip_install = true
 passenv =
@@ -13,7 +13,7 @@ deps =
   -rdev-requirements.txt
   -e.
 
-[testenv:{integration,py38,py39,py310,py311,py}-{snowflake}]
+[testenv:{integration,py39,py310,py311,py}-{snowflake}]
 description = adapter plugin integration testing
 skip_install = true
 passenv =