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#

TopicGuidanceReferenceVariables and NamingDescriptive names, avoid implicit magic, keep variable scope closereferences/variables-and-naming.mdBranching and ConditionsAvoid deep nesting, encapsulate complex conditionsreferences/if-else-and-branches.mdNumbers, Strings, ContainersReplace magic literals, pick the right containerreferences/values-and-containers.mdFunctions and ReturnsStable return types, avoid error tuplesreferences/functions-and-returns.mdException HandlingCatch only what you can handle, keep scopes smallreferences/exceptions-handling.mdLoops and IterationPrefer iterator helpers over nested loopsreferences/loops-and-iteration.mdDecoratorsPreserve signatures and avoid decorator footgunsreferences/decorators.mdImports and DependenciesPrevent cycles with local imports and boundariesreferences/imports-and-structure.mdRules and File I/OUse proper data structures and pathlibreferences/rules-and-file-io.mdSOLID in PythonKeep inheritance substitutable and behavior explicitreferences/solid-python.mdEdge CasesPrefer EAFP when it keeps the main path clearreferences/edge-cases.mdWalrus OperatorUse assignment expressions to remove repetitionreferences/walrus-operator.md

References#

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