feat: python 3.14 support (#6712)

## 📝 Summary

Add python 3.14 (🥧!) to our ci
(https://docs.python.org/3.14/whatsnew/3.14.html)

<img width="447" height="140" alt="image"
src="https://github.com/user-attachments/assets/2dbd0183-0abe-4464-9b56-fed17fd0d80d"
/>

Also add a note to remove 3.9 in a month
(https://devguide.python.org/versions/)

---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

Author: dmadisetti

.github/workflows/test_be.yaml

@@ -59,11 +59,11 @@ jobs:
       matrix:
         os: [ubuntu-latest, macos-latest, windows-latest]
         dependencies: ["core", "core,optional"]
-        python-version: ["3.9"]
+        python-version: ["3.10"]
         include:
           - os: ubuntu-latest
             python-version: "3.10"
-            dependencies: "core"
+            dependencies: "minimal"
           - os: ubuntu-latest
             python-version: "3.11"
             dependencies: "core"
@@ -74,8 +74,8 @@ jobs:
             python-version: "3.13"
             dependencies: "core"
           - os: ubuntu-latest
-            python-version: "3.9"
-            dependencies: "core,optional"
+            python-version: "3.14"
+            dependencies: "core"
           - os: ubuntu-latest
             python-version: "3.10"
             dependencies: "core,optional"
@@ -88,9 +88,7 @@ jobs:
           - os: ubuntu-latest
             python-version: "3.13"
             dependencies: "core,optional"
-          - os: ubuntu-latest
-            python-version: "3.9"
-            dependencies: "minimal"
+          # TODO: Add in 3.14 optional once there is broader wheel support
     steps:
       - name: 🛑 Cancel Previous Runs
         uses: styfle/cancel-workflow-action@0.12.1
@@ -115,6 +113,11 @@ jobs:
         if: ${{ matrix.python-version == '3.12' }}
         run: hatch run typecheck:check
 
+      # Required since python3.14 not pulled automatically for now.
+      - uses: actions/setup-python@v6
+        with:
+          python-version: ${{ matrix.python-version }}
+
       # Test with base dependencies
       - name: Test with base dependencies
         if: ${{ matrix.dependencies == 'core' }}

marimo/_messaging/ops.py

@@ -614,7 +614,7 @@ class ColumnPreview(msgspec.Struct):
 
 
 # We shouldn't need to make table_name and column_name have default values.
-# We can use kw_only=True once we drop support for Python 3.9.
+# We can use kw_only=True once we drop support for Python 3.9 (25-11-01).
 class DataColumnPreview(Op, ColumnPreview, tag="data-column-preview"):
     """Preview of a column in a dataset."""
 

marimo/_plugins/ui/_core/registry.py

@@ -22,7 +22,7 @@
 
 T = TypeVar("T")
 
-# Recursive types don't support | or dict[] in py3.8/3.9
+# Recursive types don't support | or dict[] in py3.8/3.9 (25-11-01)
 LensValue: TypeAlias = Union[T, dict[str, "LensValue[T]"]]
 
 

pixi.lock

@@ -20,7 +20,7 @@ dependencies = [
     # Pinned to specific version for introduction of codeblock handling.
     "pymdown-extensions>=10.15,<11",
     # syntax highlighting of code in markdown
-    "pygments>=2.13,<3",
+    "pygments>=2.19,<3",
     # for reading, writing configs
     "tomlkit>= 0.12.0",
     # for managing frontmatter headers in markdown
@@ -36,7 +36,7 @@ dependencies = [
     # websockets for use with starlette, and for lsp
     "websockets >= 14.2.0",
     # loro for collaborative editing
-    "loro>=1.5.0; python_version >= '3.11'",
+    "loro>=1.5.0; python_version >= '3.11' and python_version < '3.14'",
     # python <=3.10 compatibility
     "typing_extensions>=4.4.0; python_version < '3.11'",
     # for rst parsing; lowerbound determined by awscli requiring < 0.17,
@@ -68,6 +68,7 @@ classifiers = [
     "Programming Language :: Python :: 3.11",
     "Programming Language :: Python :: 3.12",
     "Programming Language :: Python :: 3.13",
+    "Programming Language :: Python :: 3.14",
     "Programming Language :: Python :: 3 :: Only",
 ]
 
@@ -195,18 +196,21 @@ extra-dependencies = [
     "hypothesis~=6.102.1",
     # For server testing
     "httpx~=0.27.0",
-    "matplotlib~=3.9.2",
+    "urllib3~=2.5.0",
+    "matplotlib~=3.10.7",
+    # Forced for modern matplotlib.
+    "pillow>=9",
     "pytest~=8.3.4",
     "pytest-timeout~=2.3.1",
-    "pytest-codecov~=0.6.1",
+    "pytest-codecov~=0.7.0",
     "pytest-rerunfailures~=15.1",
     "pytest-asyncio~=0.26.0",
     "pytest-picked>=0.5.1",
     "inline-snapshot~=0.29.0",
 ]
 
 [[tool.hatch.envs.test.matrix]]
-python = ["3.9", "3.10", "3.11", "3.12", "3.13"]
+python = ["3.9", "3.10", "3.11", "3.12", "3.13", "3.14"]
 
 [tool.hatch.envs.test.scripts]
 test = "pytest{env:HATCH_TEST_ARGS:} {args:tests}"
@@ -284,7 +288,7 @@ extra-dependencies = [
 ]
 
 [[tool.hatch.envs.test-optional.matrix]]
-python = ["3.9", "3.10", "3.11", "3.12", "3.13"]
+python = ["3.9", "3.10", "3.11", "3.12", "3.13", "3.14"]
 
 [tool.hatch.envs.docs]
 dependencies = [

pyproject.toml

@@ -110,7 +110,9 @@ def rtc_enabled(config: UserConfigManager):
 ws_2_sync = "/ws_sync?session_id=456&access_token=fake-token"
 
 
-@pytest.mark.skipif("sys.version_info < (3, 11)")
+@pytest.mark.skipif(
+    "sys.version_info < (3, 11) or sys.version_info >= (3, 14)"
+)
 async def test_loro_sync(client: TestClient) -> None:
     """Test that Loro-CRDT sync works between multiple clients"""
 
@@ -147,7 +149,9 @@ async def test_loro_sync(client: TestClient) -> None:
     client.post("/api/kernel/shutdown", headers=HEADERS)
 
 
-@pytest.mark.skipif("sys.version_info < (3, 11)")
+@pytest.mark.skipif(
+    "sys.version_info < (3, 11) or sys.version_info >= (3, 14)"
+)
 async def test_loro_cleanup_on_session_close(
     client: TestClient,
 ) -> None:
@@ -192,7 +196,9 @@ async def test_loro_cleanup_on_session_close(
     client.post("/api/kernel/shutdown", headers=HEADERS)
 
 
-@pytest.mark.skipif("sys.version_info < (3, 11)")
+@pytest.mark.skipif(
+    "sys.version_info < (3, 11) or sys.version_info >= (3, 14)"
+)
 async def test_loro_persistence(client: TestClient) -> None:
     """Test that cell content persists between connections"""
     from loro import ExportMode, LoroDoc

tests/_server/api/endpoints/test_ws_rtc.py

@@ -9,7 +9,7 @@
 from marimo._server.rtc.doc import LoroDocManager
 from marimo._types.ids import CellId_t
 
-if sys.version_info >= (3, 11):
+if sys.version_info >= (3, 11) and sys.version_info < (3, 14):
     from loro import LoroDoc, LoroText
 
 doc_manager = LoroDocManager()
@@ -29,7 +29,9 @@ async def setup_doc_manager() -> AsyncGenerator[None, None]:
     doc_manager.loro_docs_cleaners.clear()
 
 
-@pytest.mark.skipif("sys.version_info < (3, 11)")
+@pytest.mark.skipif(
+    "sys.version_info < (3, 11) or sys.version_info >= (3, 14)"
+)
 async def test_quick_reconnection(setup_doc_manager: None) -> None:
     """Test that quick reconnection properly handles cleanup task cancellation"""
     del setup_doc_manager
@@ -65,7 +67,9 @@ async def test_quick_reconnection(setup_doc_manager: None) -> None:
     )  # Original client + reconnected client
 
 
-@pytest.mark.skipif("sys.version_info < (3, 11)")
+@pytest.mark.skipif(
+    "sys.version_info < (3, 11) or sys.version_info >= (3, 14)"
+)
 async def test_two_users_sync(setup_doc_manager: None) -> None:
     """Test that two users can connect and sync text properly without duplicates"""
     del setup_doc_manager
@@ -111,7 +115,9 @@ async def test_two_users_sync(setup_doc_manager: None) -> None:
     assert lang_text_typed.to_string() == "python"
 
 
-@pytest.mark.skipif("sys.version_info < (3, 11)")
+@pytest.mark.skipif(
+    "sys.version_info < (3, 11) or sys.version_info >= (3, 14)"
+)
 async def test_concurrent_doc_creation(setup_doc_manager: None) -> None:
     """Test concurrent doc creation doesn't cause issues"""
     del setup_doc_manager
@@ -130,7 +136,9 @@ async def test_concurrent_doc_creation(setup_doc_manager: None) -> None:
     assert len(doc_manager.loro_docs) == 1
 
 
-@pytest.mark.skipif("sys.version_info < (3, 11)")
+@pytest.mark.skipif(
+    "sys.version_info < (3, 11) or sys.version_info >= (3, 14)"
+)
 async def test_concurrent_client_operations(
     setup_doc_manager: None,
 ) -> None:
@@ -157,7 +165,9 @@ async def client_operation(queue: asyncio.Queue[bytes]) -> None:
     assert len(doc_manager.loro_docs_clients[file_key]) == 0
 
 
-@pytest.mark.skipif("sys.version_info < (3, 11)")
+@pytest.mark.skipif(
+    "sys.version_info < (3, 11) or sys.version_info >= (3, 14)"
+)
 async def test_cleanup_task_management(setup_doc_manager: None) -> None:
     """Test cleanup task management and cancellation"""
     del setup_doc_manager
@@ -189,7 +199,9 @@ async def test_cleanup_task_management(setup_doc_manager: None) -> None:
     await doc_manager.remove_client(file_key, new_queue)
 
 
-@pytest.mark.skipif("sys.version_info < (3, 11)")
+@pytest.mark.skipif(
+    "sys.version_info < (3, 11) or sys.version_info >= (3, 14)"
+)
 async def test_broadcast_update(setup_doc_manager: None) -> None:
     """Test broadcast update functionality"""
     del setup_doc_manager
@@ -215,7 +227,9 @@ async def test_broadcast_update(setup_doc_manager: None) -> None:
             assert await queue.get() == message
 
 
-@pytest.mark.skipif("sys.version_info < (3, 11)")
+@pytest.mark.skipif(
+    "sys.version_info < (3, 11) or sys.version_info >= (3, 14)"
+)
 async def test_remove_nonexistent_doc(setup_doc_manager: None) -> None:
     """Test removing a doc that doesn't exist"""
     del setup_doc_manager
@@ -226,7 +240,9 @@ async def test_remove_nonexistent_doc(setup_doc_manager: None) -> None:
     assert file_key not in doc_manager.loro_docs_cleaners
 
 
-@pytest.mark.skipif("sys.version_info < (3, 11)")
+@pytest.mark.skipif(
+    "sys.version_info < (3, 11) or sys.version_info >= (3, 14)"
+)
 async def test_remove_nonexistent_client(setup_doc_manager: None) -> None:
     """Test removing a client that doesn't exist"""
     del setup_doc_manager
@@ -236,7 +252,9 @@ async def test_remove_nonexistent_client(setup_doc_manager: None) -> None:
     assert file_key not in doc_manager.loro_docs_clients
 
 
-@pytest.mark.skipif("sys.version_info < (3, 11)")
+@pytest.mark.skipif(
+    "sys.version_info < (3, 11) or sys.version_info >= (3, 14)"
+)
 async def test_concurrent_doc_removal(setup_doc_manager: None) -> None:
     """Test concurrent doc removal doesn't cause issues"""
     del setup_doc_manager
@@ -255,7 +273,7 @@ async def test_concurrent_doc_removal(setup_doc_manager: None) -> None:
 
 
 @pytest.mark.skipif(
-    sys.version_info < (3, 11), reason="Python 3.10+ required for Barrier"
+    "sys.version_info < (3, 11) or sys.version_info >= (3, 14)"
 )
 async def test_prevent_lock_deadlock(setup_doc_manager: None) -> None:
     """Test that our deadlock prevention measures work correctly.