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

User Need Use This Skill Alternative Skill

"make this pythonic" ✅ Yes - Python standards

"is this good python" ✅ Yes - code quality

"type hints" ✅ Yes - typing guidance

"LBYL vs EAFP" ✅ Yes - exception patterns

"pathlib vs os.path" ✅ Yes - path handling

"best practices for dagster" ❌ No /dagster-best-practices

"implement X pipeline" ❌ No /dg for implementation

"which integration to use" ❌ No /dagster-expert

"CLI argument parsing" ✅ Yes - CLI patterns

Core Knowledge (ALWAYS Loaded)

@dignified-python-core.md

Version Detection

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

• pyproject.toml

• Look for requires-python field (e.g., requires-python = ">=3.12" )

• setup.py or setup.cfg

• Look for python_requires

• .python-version file - Contains version like 3.12 or 3.12.0

• 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

• Core knowledge is loaded automatically (LBYL, pathlib, basic imports, anti-patterns)

• Version detection happens once - identify the minimum Python version and load the appropriate version file

• Reference documents are loaded on-demand based on the triggers above

• Additional patterns may require extra loading (CLI patterns, subprocess)

• Each file is self-contained with complete guidance for its domain