Dignified Python Coding Standards Skill

Production-quality Python coding standards for writing clean, maintainable, modern Python code (versions 3.10-3.13).

When to Use This Skill

Auto-invoke when users ask about:

• •"make this pythonic" / "is this good python"
• •"type hints" / "type annotations" / "typing"
• •"LBYL vs EAFP" / "exception handling"
• •"pathlib vs os.path" / "path operations"
• •"CLI patterns" / "click usage"
• •"code review" / "improve this code"
• •Any Python code quality or standards question

Note: This skill is general Python standards, not Dagster-specific. Use /dagster-best-practices for Dagster patterns.

When to Use This Skill vs. Others

Core Knowledge (ALWAYS Loaded)

@dignified-python-core.md

Version Detection

Identify the project's minimum Python version by checking (in order):

1. •pyproject.toml - Look for requires-python field (e.g., requires-python = ">=3.12")
2. •setup.py or setup.cfg - Look for python_requires
3. •.python-version file - Contains version like 3.12 or 3.12.0
4. •Default to Python 3.12 if no version specifier found

Once identified, load the appropriate version-specific file:

• •Python 3.10: Load versions/python-3.10.md
• •Python 3.11: Load versions/python-3.11.md
• •Python 3.12: Load versions/python-3.12.md
• •Python 3.13: Load versions/python-3.13.md

Conditional Loading (Load Based on Task Patterns)

Core files above cover 80%+ of Python code patterns. Only load these additional files when you detect specific patterns:

Pattern detection examples:

• •If task mentions "click" or "CLI" -> Load references/cli-patterns.md
• •If task mentions "subprocess" -> Load subprocess patterns from core-standards

Reference Documentation Structure

The references/ directory contains detailed guidance organized by topic:

Core References

• •core-standards.md - Essential standards (always loaded)
• •cli-patterns.md - Command-line interface patterns (click, argparse)

Version-Specific References (references/versions/)

• •python-3.10.md - Features available in Python 3.10+
• •python-3.11.md - Features available in Python 3.11+
• •python-3.12.md - Features available in Python 3.12+
• •python-3.13.md - Features available in Python 3.13+

Advanced Topics (references/advanced/)

• •exception-handling.md - LBYL patterns, error boundaries
• •interfaces.md - ABC and Protocol patterns
• •typing-advanced.md - Advanced typing patterns
• •api-design.md - API design principles

When to Read Each Reference Document

references/advanced/exception-handling.md

Read when:

• •Writing try/except blocks
• •Wrapping third-party APIs that may raise
• •Seeing or writing from e or from None
• •Unsure if LBYL alternative exists

references/advanced/interfaces.md

Read when:

• •Creating ABC or Protocol classes
• •Writing @abstractmethod decorators
• •Designing gateway layer interfaces
• •Choosing between ABC and Protocol

references/advanced/typing-advanced.md

Read when:

• •Using typing.cast()
• •Creating Literal type aliases
• •Narrowing types in conditional blocks

references/module-design.md

Read when:

• •Creating new Python modules
• •Adding module-level code (beyond simple constants)
• •Using @cache decorator at module level
• •Seeing Path() or computation at module level
• •Considering inline imports

references/api-design.md

Read when:

• •Adding default parameter values to functions
• •Defining functions with 5 or more parameters
• •Using ThreadPoolExecutor.submit()
• •Reviewing function signatures

references/checklists.md

Read when:

• •Final review before committing Python code
• •Unsure if you've followed all rules
• •Need a quick lookup of requirements

How to Use This Skill

1. •Core knowledge is loaded automatically (LBYL, pathlib, basic imports, anti-patterns)
2. •Version detection happens once - identify the minimum Python version and load the appropriate version file
3. •Reference documents are loaded on-demand based on the triggers above
4. •Additional patterns may require extra loading (CLI patterns, subprocess)
5. •Each file is self-contained with complete guidance for its domain