Python Deployment Checklist

Version: 1.1.0 | Updated: 2026-07-16

Purpose

Gate promotion and rollback of a Python package, FastAPI/Django boundary, asyncio task, worker, or library API.

Why

A syntactically valid Python artifact can still fail because of environment or import resolution mismatch, unawaited coroutine or lost cancellation, blocking work in the event loop, resource/session leak, schema or type contract drift. Promotion therefore requires target-state and rollback evidence.

How

Run against the exact target and immutable candidate. Preserve outputs from python --version and python -m pip check; python -m pytest -q with the repository configuration; python -m ruff check . when Ruff is declared; python -m mypy . when mypy is declared; PYTHONASYNCIODEBUG=1 python -m <module> for asyncio diagnostics. Stop promotion on any failed item.

Version-aware caution

Read requires-python, lock/constraint files, environment metadata, and framework pins. Typing syntax, asyncio behavior, packaging metadata, and standard-library APIs differ by Python minor release; use the deployed interpreter's documentation.

Tradeoffs

Promotion waits for "artifact is built once and installed into a clean environment with locked dependencies" and "deployed Python minor and native-wheel platform match build evidence". Those Python target checks slow release but directly bound environment or import resolution mismatch and make this rollback executable: Stop producers before reverting consumers when task schemas changed; deploy the previous wheel/image only after confirming database and serialized payload compatibility.

Anti-patterns

• Calling asyncio.create_task without retained ownership loses exceptions, cancellation, and shutdown guarantees.
• Do not remove a native warning, validator, policy, or safety limit merely to make generated output pass.
• Do not claim a successful result without preserving the command, target, artifact/revision, and observed output.

Enterprise considerations

Python governance requires approved indexes, hash-locked dependencies, native-wheel provenance, supported interpreter lines, and controls for notebook or dynamic-code execution.

Official sources

• Python documentation
• asyncio
• Packaging User Guide
• Typing specification

Checklist

• artifact is built once and installed into a clean environment with locked dependencies.
• deployed Python minor and native-wheel platform match build evidence.
• database migrations and worker/application rollout order are backward compatible.
• ASGI/WSGI worker, timeout, keepalive, and pool settings are load-tested.
• startup imports, health checks, signal handling, and graceful worker drain pass.
• tracebacks, task failures, queue depth, pool usage, and memory are observable.
• canary checks error classes and latency by worker/process.
• rollback retains compatibility with queued task payloads and migrated schema.
• Stop producers before reverting consumers when task schemas changed; deploy the previous wheel/image only after confirming database and serialized payload compatibility.
• Evidence identifies version, target, artifact/revision, command or manual method, UTC time, and result.

Changelog

• 1.1.0 (2026-07-16): Replaced generic gates with native Python evidence and failure controls.
• 1.0.0 (2026-07-16): Added initial checklist.