Python Language

Priority: P0 (CRITICAL)

Rules

• Prefer from __future__ import annotations in modern modules.
• Type public functions, return values, and boundary data shapes.
• Use pathlib.Path, contextlib, enum, and stdlib helpers before custom wrappers.
• Use @dataclass(frozen=True) for immutable contracts and value objects.
• Prefer Protocol, TypedDict, or small dataclasses over dict[str, Any] sprawl.

Recipe

1. Model contracts explicitly with dataclasses, typed dicts, or pydantic at I/O boundaries.
2. Keep imports stable: stdlib, third-party, local.
3. Use comprehensions and generators carefully; stop when readability drops.
4. Choose explicit timezone-aware datetimes for persisted or user-visible timestamps.
5. Keep module side effects minimal; import should not start work.