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name: Python Patterns description: This skill should be used when the user asks about "Python best practices", "Pythonic code", "Python patterns", "Python idioms", "type hints", "dataclasses", "async Python", "Python decorators", "context managers" version: 1.0.0

Python Patterns

Guidance for writing idiomatic, modern Python code.

Modern Python Features (3.9+)

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Type Hints

Modern syntax (3.10+): Use | for unions, built-in types for generics.

Key concept: Type hints are for tooling (mypy, IDEs) - no runtime enforcement.

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Dataclasses vs Alternatives

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Context Managers

Use for any resource that needs cleanup: files, connections, locks, transactions.

Pattern: Acquire in __enter__, release in __exit__ (or use @contextmanager with yield)

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Decorators

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Async Python

When to use: I/O-bound operations (HTTP requests, DB queries, file I/O)

When NOT to use: CPU-bound operations (use multiprocessing instead)

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Pythonic Idioms

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Project Structure

Copymy_project/
├── src/my_package/     # Source code
├── tests/              # Test files
├── pyproject.toml      # Project config
└── README.md

Key concept: Use src/ layout to prevent import confusion.

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Tooling

Resources

• Python docs: https://docs.python.org/3/
• Real Python: https://realpython.com/