Python Libraries

Python Libraries

Prefer well-supported libraries (and the standard library) over hand-rolled code — it is less to maintain and less to get wrong than reinventing a solved problem.

Don't reinvent the wheel

• Don't hand-roll retry or backoff loops — use stamina (it wraps tenacity with sane

defaults: capped attempts, jitter, and retrying only the exceptions you name). Set a timeout and exclude non-retryable errors, such as a 4xx that won't change on retry.

• Don't reimplement what itertools (stdlib) or more-itertools already provide

(grouping, chaining, windowing, accumulating) — reach for them instead. See python-code-style for the broader "prefer stdlib idioms" rule.

• Don't parse HTML or XML with regex — use parsel (XPath and CSS selectors).

HTTP

• Use an HTTP client with async support — this rules out requests and urllib.
• Match the async client the repo already uses rather than introducing a second one, and

don't add another HTTP client as a (dev) dependency without a concrete reason.

• Set an explicit timeout on outbound requests; a single client-level default is fine,

but never rely on the library default, which is often None (waits forever).

JSON

• Use orjson over the standard library json for serialising and deserialising — it is

faster and better-behaved.

• When a Pydantic model is involved, go straight to and from JSON bytes with

Model.model_validate_json(raw) and model.model_dump_json() — one fast parse-and-validate pass.

• Don't call an HTTP response's .json() and hand the resulting dict to Pydantic: that

parses twice (the client builds a dict, then Pydantic re-validates it). Pass the raw bytes (response.content) to Model.model_validate_json(...) instead.

See python-async for deploying on uvloop, and python-datetime for dates and times.

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: owenlamont
• Source: owenlamont/agent_skills
• License: MIT

Install and usage instructions live in the source repository linked above.