Governance Standards Application Python

Python

Standards for generated Python application code, including project structure, dependency management, and Azure SDK patterns.

5 principles

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ID	Principle	Rationale
STAN-PY-001	Use Azure SDK with DefaultAzureCredential	Always use DefaultAzureCredential from azure-identity for authenticating to Azure services. This wo
STAN-PY-002	Project Structure	Python projects must have a clear structure: src/ for application code, tests/ for tests, requiremen
STAN-PY-003	Configuration via Environment Variables	Use environment variables for all configuration (loaded via os.environ or a settings class). Never
STAN-PY-004	Async for I/O-Bound Operations	Use async/await for HTTP handlers, database queries, and external API calls. Synchronous I/O blocks
STAN-PY-005	Type Annotations	Use type annotations on all function signatures and return types. This enables IDE support, document

STAN-PY-001: Use Azure SDK with DefaultAzureCredential

Always use DefaultAzureCredential from azure-identity for authenticating to Azure services. This works with managed identity in Azure and developer credentials locally.

Applies to: app-developer

Examples:

• from azure.identity import DefaultAzureCredential
• credential = DefaultAzureCredential()
• Never pass connection strings when managed identity is available

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STAN-PY-002: Project Structure

Python projects must have a clear structure: src/ for application code, tests/ for tests, requirements.txt or pyproject.toml for dependencies. Use packages (directories with init.py) for logical grouping.

Applies to: app-developer

Examples:

• src/app/ — application package
• src/app/main.py — entry point
• src/app/routes/ — API route handlers
• src/app/services/ — business logic
• tests/ — test files

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STAN-PY-003: Configuration via Environment Variables

Use environment variables for all configuration (loaded via os.environ or a settings class). Never hardcode service URLs, ports, or feature flags.

Applies to: app-developer

Examples:

• import os; port = int(os.environ.get('PORT', 8080))
• Use pydantic Settings class for type-safe config

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STAN-PY-004: Async for I/O-Bound Operations

Use async/await for HTTP handlers, database queries, and external API calls. Synchronous I/O blocks the event loop and reduces throughput.

Applies to: app-developer

Examples:

• async def get_items(db: AsyncSession) -> list[Item]:
• Use aiohttp or httpx for async HTTP clients

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STAN-PY-005: Type Annotations

Use type annotations on all function signatures and return types. This enables IDE support, documentation, and static analysis.

Applies to: app-developer

Examples:

• def get_user(user_id: str) -> User | None:
• async def create_order(order: OrderCreate) -> OrderResponse:

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