Add Python 3.14 support and drop Python 3.9 (#2787)

* Initial plan

* Add Python 3.14 support and drop Python 3.9

- Update workflow to test Python 3.10-3.14 instead of 3.9-3.13
- Update pyproject.toml to target Python 3.10 as minimum version
- Upgrade Pillow from 10.4.0 to 12.0.0 for Python 3.14 support
- Update Dockerfile to use Python 3.13-bookworm
- Update devcontainer to use Python 3.13-bookworm
- Update README and AGENTS.md documentation

Co-authored-by: pamelafox <297042+pamelafox@users.noreply.github.com>

* Fix pyproject.toml python_version format for mypy

Co-authored-by: pamelafox <297042+pamelafox@users.noreply.github.com>

* Update uv version to 0.9.5 in GitHub workflows

Co-authored-by: pamelafox <297042+pamelafox@users.noreply.github.com>

* Upgrade type annotations to Python 3.10+ syntax (X | Y)

Applied ruff check --fix to automatically upgrade type annotations:
- Replace Optional[X] with X | None
- Replace Union[X, Y] with X | Y
- Move Callable import from typing to collections.abc

This is possible now that Python 3.9 support is dropped.

Co-authored-by: pamelafox <297042+pamelafox@users.noreply.github.com>

* Upgrade pydantic-core to 2.41.4 for Python 3.14 support

Upgraded dependencies to get Python 3.14 wheel support:
- pydantic: 2.8.2 → 2.12.3
- pydantic-core: 2.20.1 → 2.41.4 (has cp314 wheels)
- openai: 1.99.8 → 2.6.1
- Also upgraded Azure SDKs and other dependencies

Verified pydantic-core 2.41.4 has Python 3.14 (cp314) wheels available
on PyPI and installs successfully.

Co-authored-by: pamelafox <297042+pamelafox@users.noreply.github.com>

* Fix openai version to stay on v1.x to avoid breaking changes

Constrained openai to <2.0 in requirements.in to prevent upgrading
to v2.x which has breaking API changes. Downgraded from 2.6.1 to
1.109.1 (latest v1.x). Kept pydantic-core at 2.41.4 for Python 3.14
support.

Co-authored-by: pamelafox <297042+pamelafox@users.noreply.github.com>

* Fix: Use minimal pydantic upgrade for Python 3.14 support

Reverted to original requirements and applied minimal upgrades:
- pydantic: 2.8.2 → 2.12.3
- pydantic-core: 2.20.1 → 2.41.4 (has cp314 wheels)
- typing-extensions: 4.13.2 → 4.15.0
- Added typing-inspection==0.4.2 (new pydantic dependency)
- Constrained openai to <2.0 in requirements.in

This avoids upgrading tiktoken, uvicorn, and other unrelated packages
that were causing test failures.

Co-authored-by: pamelafox <297042+pamelafox@users.noreply.github.com>

* Upgrade Pillow to 12.0.0 for Python 3.14 support

Pillow 10.4.0 doesn't have Python 3.14 (cp314) wheels. Upgraded to
Pillow 12.0.0 which includes cp314 wheels for Python 3.14 support.

Co-authored-by: pamelafox <297042+pamelafox@users.noreply.github.com>

* Upgrade tiktoken to 0.12.0 for Python 3.14 support

tiktoken 0.8.0 doesn't have Python 3.14 (cp314) wheels. Upgraded to
tiktoken 0.12.0 which includes cp314 wheels for Python 3.14 support.

Co-authored-by: pamelafox <297042+pamelafox@users.noreply.github.com>

* Remove unneeded upper bound on openai

* Bring back optional

* Undo unneeded change

* Fix mypy

* Add tests for missing lines

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: pamelafox <297042+pamelafox@users.noreply.github.com>
Co-authored-by: Pamela Fox <pamelafox@microsoft.com>
Co-authored-by: Pamela Fox <pamela.fox@gmail.com>

Author: Copilot

.devcontainer/devcontainer.json

@@ -1,6 +1,6 @@
 {
     "name": "Azure Search OpenAI Demo",
-    "image": "mcr.microsoft.com/devcontainers/python:3.11-bookworm",
+    "image": "mcr.microsoft.com/devcontainers/python:3.13-bookworm",
     "features": {
         "ghcr.io/devcontainers/features/node:1": {
             // This should match the version of Node.js in Github Actions workflows

.github/workflows/evaluate.yaml

@@ -128,7 +128,7 @@ jobs:
         uses: astral-sh/setup-uv@v6
         with:
           enable-cache: true
-          version: "0.4.20"
+          version: "0.9.5"
           cache-dependency-glob: "requirements**.txt"
           python-version: "3.11"
 

.github/workflows/python-test.yaml

@@ -25,7 +25,7 @@ jobs:
       fail-fast: false
       matrix:
         os: ["ubuntu-latest", "windows-latest"]
-        python_version: ["3.9", "3.10", "3.11", "3.12", "3.13"]
+        python_version: ["3.10", "3.11", "3.12", "3.13", "3.14"]
         node_version: ["20.14", "22"]
     steps:
         - uses: actions/checkout@v5
@@ -36,7 +36,7 @@ jobs:
           uses: astral-sh/setup-uv@v6
           with:
             enable-cache: true
-            version: "0.4.20"
+            version: "0.9.5"
             cache-dependency-glob: "requirements**.txt"
             python-version: ${{ matrix.python_version }}
             activate-environment: true

.pre-commit-config.yaml

@@ -7,7 +7,7 @@ repos:
     -   id: end-of-file-fixer
     -   id: trailing-whitespace
 -   repo: https://github.com/astral-sh/ruff-pre-commit
-    rev: v0.9.3
+    rev: v0.14.2
     hooks:
     -   id: ruff
 -   repo: https://github.com/psf/black

AGENTS.md

@@ -86,6 +86,18 @@ When you're running tests, make sure you activate the .venv virtual environment
 source .venv/bin/activate
 ```
 
+To check for coverage, run the following command:
+
+```shell
+pytest --cov --cov-report=annotate:cov_annotate
+```
+
+Open the cov_annotate directory to view the annotated source code. There will be one file per source file. If a file has 100% source coverage, it means all lines are covered by tests, so you do not need to open the file.
+
+For each file that has less than 100% test coverage, find the matching file in cov_annotate and review the file.
+
+If a line starts with a ! (exclamation mark), it means that the line is not covered by tests. Add tests to cover the missing lines.
+
 ## Sending pull requests
 
 When sending pull requests, make sure to follow the PULL_REQUEST_TEMPLATE.md format.
@@ -95,15 +107,15 @@ When sending pull requests, make sure to follow the PULL_REQUEST_TEMPLATE.md for
 To upgrade a particular package in the backend, use the following command, replacing `<package-name>` with the name of the package you want to upgrade:
 
 ```shell
-cd app/backend && uv pip compile requirements.in -o requirements.txt --python-version 3.9 --upgrade-package package-name
+cd app/backend && uv pip compile requirements.in -o requirements.txt --python-version 3.10 --upgrade-package package-name
 ```
 
 ## Checking Python type hints
 
 To check Python type hints, use the following command:
 
 ```shell
-cd app/backend && mypy . --config-file=../pyproject.toml
+cd app/backend && mypy . --config-file=../../pyproject.toml
 ```
 
 ```shell

README.md

@@ -131,7 +131,7 @@ A related option is VS Code Dev Containers, which will open the project in your
 1. Install the required tools:
 
     - [Azure Developer CLI](https://aka.ms/azure-dev/install)
-    - [Python 3.9, 3.10, or 3.11](https://www.python.org/downloads/)
+    - [Python 3.10, 3.11, 3.12, 3.13, or 3.14](https://www.python.org/downloads/)
       - **Important**: Python and the pip package manager must be in the path in Windows for the setup scripts to work.
       - **Important**: Ensure you can run `python --version` from console. On Ubuntu, you might need to run `sudo apt install python-is-python3` to link `python` to `python3`.
     - [Node.js 20+](https://nodejs.org/download/)

app/backend/Dockerfile

@@ -1,4 +1,4 @@
-FROM python:3.11-bullseye
+FROM python:3.13-bookworm
 
 WORKDIR /app
 

app/backend/app.py

@@ -5,9 +5,9 @@
 import mimetypes
 import os
 import time
-from collections.abc import AsyncGenerator, Awaitable
+from collections.abc import AsyncGenerator, Awaitable, Callable
 from pathlib import Path
-from typing import Any, Callable, Union, cast
+from typing import Any, cast
 
 from azure.cognitiveservices.speech import (
     ResultReason,
@@ -477,7 +477,7 @@ async def setup_clients():
     # Use the current user identity for keyless authentication to Azure services.
     # This assumes you use 'azd auth login' locally, and managed identity when deployed on Azure.
     # The managed identity is setup in the infra/ folder.
-    azure_credential: Union[AzureDeveloperCliCredential, ManagedIdentityCredential]
+    azure_credential: AzureDeveloperCliCredential | ManagedIdentityCredential
     azure_ai_token_provider: Callable[[], Awaitable[str]]
     if RUNNING_ON_AZURE:
         current_app.logger.info("Setting up Azure credential using ManagedIdentityCredential")

app/backend/approaches/approach.py

@@ -2,7 +2,7 @@
 from abc import ABC
 from collections.abc import AsyncGenerator, Awaitable
 from dataclasses import dataclass, field
-from typing import Any, Optional, TypedDict, Union, cast
+from typing import Any, Optional, TypedDict, cast
 
 from azure.search.documents.agent.aio import KnowledgeAgentRetrievalClient
 from azure.search.documents.agent.models import (
@@ -190,7 +190,7 @@ def build_filter(self, overrides: dict[str, Any]) -> Optional[str]:
             filters.append("category eq '{}'".format(include_category.replace("'", "''")))
         if exclude_category:
             filters.append("category ne '{}'".format(exclude_category.replace("'", "''")))
-        return None if len(filters) == 0 else " and ".join(filters)
+        return None if not filters else " and ".join(filters)
 
     async def search(
         self,
@@ -520,7 +520,7 @@ def create_chat_completion(
         temperature: Optional[float] = None,
         n: Optional[int] = None,
         reasoning_effort: Optional[ChatCompletionReasoningEffort] = None,
-    ) -> Union[Awaitable[ChatCompletion], Awaitable[AsyncStream[ChatCompletionChunk]]]:
+    ) -> Awaitable[ChatCompletion] | Awaitable[AsyncStream[ChatCompletionChunk]]:
         if chatgpt_model in self.GPT_REASONING_MODELS:
             params: dict[str, Any] = {
                 # max_tokens is not supported

app/backend/approaches/chatreadretrieveread.py

@@ -1,7 +1,7 @@
 import json
 import re
 from collections.abc import AsyncGenerator, Awaitable
-from typing import Any, Optional, Union, cast
+from typing import Any, Optional, cast
 
 from azure.search.documents.agent.aio import KnowledgeAgentRetrievalClient
 from azure.search.documents.aio import SearchClient
@@ -215,7 +215,7 @@ async def run_until_final_call(
         overrides: dict[str, Any],
         auth_claims: dict[str, Any],
         should_stream: bool = False,
-    ) -> tuple[ExtraInfo, Union[Awaitable[ChatCompletion], Awaitable[AsyncStream[ChatCompletionChunk]]]]:
+    ) -> tuple[ExtraInfo, Awaitable[ChatCompletion] | Awaitable[AsyncStream[ChatCompletionChunk]]]:
         use_agentic_retrieval = True if overrides.get("use_agentic_retrieval") else False
         original_user_query = messages[-1]["content"]
 
@@ -243,7 +243,7 @@ async def run_until_final_call(
         )
 
         chat_coroutine = cast(
-            Union[Awaitable[ChatCompletion], Awaitable[AsyncStream[ChatCompletionChunk]]],
+            Awaitable[ChatCompletion] | Awaitable[AsyncStream[ChatCompletionChunk]],
             self.create_chat_completion(
                 self.chatgpt_deployment,
                 self.chatgpt_model,