chore: drop support for Python 3.9 (EOL)

.github/workflows/ci-checks.yml

@@ -30,13 +30,14 @@ jobs:
       testing-matrix: |
         {
           "os": ["ubuntu-latest", "macos-14", "windows-latest"],
-          "python-version": ["3.9", "3.10"]
+          "python-version": ["3.10", "3.11"]
         }
 
   check-docs:
     uses: Lightning-AI/utilities/.github/workflows/check-docs.yml@main
     with:
       requirements-file: "requirements/docs.txt"
+      python-version: "3.10"
 
   check-md-links:
     uses: Lightning-AI/utilities/.github/workflows/check-md-links.yml@main

.github/workflows/ci-testing.yml

@@ -19,7 +19,7 @@ jobs:
       fail-fast: false
       matrix:
         os: ["ubuntu-22.04", "macos-14", "windows-2022"]
-        python-version: ["3.9", "3.10", "3.11", "3.12", "3.13", "3.14"]
+        python-version: ["3.10", "3.11", "3.12", "3.13", "3.14"]
         exclude:
           - { os: "windows-2022", python-version: "3.13" }
           - { os: "windows-2022", python-version: "3.14" }

.github/workflows/docs-build.yml

@@ -11,6 +11,7 @@ jobs:
     uses: Lightning-AI/utilities/.github/workflows/check-docs.yml@main
     with:
       requirements-file: "requirements/docs.txt"
+      python-version: "3.10"
 
   # https://github.com/marketplace/actions/deploy-to-github-pages
   docs-deploy:

pyproject.toml

@@ -13,13 +13,10 @@
 # limitations under the License.
 
 [build-system]
-requires = [
-  "setuptools",
-  "wheel",
-]
+requires = [ "setuptools", "wheel" ]
 
 [tool.ruff]
-target-version = "py39"
+target-version = "py310"
 line-length = 120
 # Exclude a variety of commonly ignored directories.
 exclude = [
@@ -48,8 +45,10 @@ lint.extend-select = [
   "SIM",    # see: https://pypi.org/project/flake8-simplify
 ]
 lint.ignore = [
-  "E731", # Do not assign a lambda expression, use a def
-  "S101", # todo: Use of `assert` detected
+  "E731",  # Do not assign a lambda expression, use a def
+  "S101",  # todo: Use of `assert` detected
+  "UP007", # todo: non-pep604-annotation-union
+  "UP045", # todo: non-pep604-annotation-optional
 ]
 lint.per-file-ignores."examples/**" = [
   "D100",
@@ -119,29 +118,17 @@ wrap-descriptions = 120
 blank = true
 
 [tool.pytest.ini_options]
-testpaths = [
-  "tests",
-]
-norecursedirs = [
-  ".git",
-  ".github",
-  "dist",
-  "build",
-  "docs",
-]
+testpaths = [ "tests" ]
+norecursedirs = [ ".git", ".github", "dist", "build", "docs" ]
 addopts = [
   "--strict-markers",
   "--doctest-modules",
   "--color=yes",
   "--disable-pytest-warnings",
   "--ignore=legacy/checkpoints",
 ]
-markers = [
-  "cloud: Run the cloud tests for example",
-]
-filterwarnings = [
-  "error::FutureWarning",
-]
+markers = [ "cloud: Run the cloud tests for example" ]
+filterwarnings = [ "error::FutureWarning" ]
 xfail_strict = true
 junit_duration_report = "call"
 
@@ -155,9 +142,7 @@ exclude_lines = [
 ]
 
 [tool.mypy]
-files = [
-  "src",
-]
+files = [ "src" ]
 # This section is for folders with "-" as they are not valid python modules
 exclude = [
   "src/litdata/utilities/_pytree.py",
@@ -190,6 +175,5 @@ warn_no_return = "False"
 [[tool.mypy.overrides]]
 # the list can be generated with:
 # mypy --no-error-summary 2>&1 | tr ':' ' ' | awk '{print $1}' | sort | uniq | sed 's/\.py//g; s|src/||g;  s|\/|\.|g' | xargs -I {} echo '"{}",'
-module = [
-]
+module = [  ]
 ignore_errors = "True"

setup.py

@@ -71,7 +71,7 @@ def _prepare_extras(requirements_dir: str = _PATH_REQUIRES, skip_files: tuple =
     include_package_data=True,
     zip_safe=False,
     keywords=["deep learning", "pytorch", "AI", "streaming", "cloud", "data processing"],
-    python_requires=">=3.9",
+    python_requires=">=3.10",
     setup_requires=["wheel"],
     install_requires=_load_requirements(),
     extras_require=_prepare_extras(),
@@ -95,7 +95,6 @@ def _prepare_extras(requirements_dir: str = _PATH_REQUIRES, skip_files: tuple =
         # Specify the Python versions you support here. In particular, ensure
         # that you indicate whether you support Python 2, Python 3 or both.
         "Programming Language :: Python :: 3",
-        "Programming Language :: Python :: 3.9",
         "Programming Language :: Python :: 3.10",
         "Programming Language :: Python :: 3.11",
         "Programming Language :: Python :: 3.12",