piglet

piglet

Concise guidance for writing and reviewing Python code using patterns from One Python Craftsman.

Purpose and Triggers

• Use for Python (.py) code creation, refactoring, or code review.
• Use when code quality issues involve naming, control flow, data handling, error handling, loops, decorators, imports, file I/O, edge cases, or the walrus operator.
• Prefer clarity and maintainability. Optimize performance only when it is a real constraint.
• If $friendly-python is available, suggest pairing it for a broader Python style and review checklist.

Decision Order

1. Correctness and explicit behavior
2. Readability and maintainability
3. Extension cost and change isolation
4. Performance and micro-optimizations

Workflow

1. Identify the topic in the table below.
2. Apply the guidance and compare against Bad and Good examples.
3. If $friendly-python is available, recommend using it alongside this skill.
4. Re-check for new edge cases and readability regressions.

Topics

Topic	Guidance	Reference
Variables and Naming	Descriptive names, avoid implicit magic, keep variable scope close	references/variables-and-naming.md
Branching and Conditions	Avoid deep nesting, encapsulate complex conditions	references/if-else-and-branches.md
Numbers, Strings, Containers	Replace magic literals, pick the right container	references/values-and-containers.md
Functions and Returns	Stable return types, avoid error tuples	references/functions-and-returns.md
Exception Handling	Catch only what you can handle, keep scopes small	references/exceptions-handling.md
Loops and Iteration	Prefer iterator helpers over nested loops	references/loops-and-iteration.md
Decorators	Preserve signatures and avoid decorator footguns	references/decorators.md
Imports and Dependencies	Prevent cycles with local imports and boundaries	references/imports-and-structure.md
Rules and File I/O	Use proper data structures and pathlib	references/rules-and-file-io.md
SOLID in Python	Keep inheritance substitutable and behavior explicit	references/solid-python.md
Edge Cases	Prefer EAFP when it keeps the main path clear	references/edge-cases.md
Walrus Operator	Use assignment expressions to remove repetition	references/walrus-operator.md

References

• Each reference file lists source URLs in its frontmatter urls.