petfeed/.claude/rules/ecc/python/patterns.md

paths

paths
**/*.py **/*.pyi

Python Patterns

This file extends common/patterns.md with Python specific content.

Protocol (Duck Typing)

from typing import Protocol

class Repository(Protocol):
    def find_by_id(self, id: str) -> dict | None: ...
    def save(self, entity: dict) -> dict: ...

Dataclasses as DTOs

from dataclasses import dataclass

@dataclass
class CreateUserRequest:
    name: str
    email: str
    age: int | None = None

Context Managers & Generators

• Use context managers (with statement) for resource management
• Use generators for lazy evaluation and memory-efficient iteration

Reference

See skill: python-patterns for comprehensive patterns including decorators, concurrency, and package organization.