CLAUDE.md

MicroImpute - Developer Guide

Code Style Guidelines

Formatting & Organization

• Use 4 spaces for indentation
• Maximum line length: 79 characters (Black default)
• Format code with Black: black microimpute/
• Sort imports with isort: isort microimpute/
• IMPORTANT: All files must end with a newline character
  • This is enforced by the linecheck tool in CI
  • Run make check-format locally before pushing to catch these errors

Naming & Types

• Use snake_case for variables, functions, and modules
• Use CamelCase for classes
• Constants should be UPPERCASE
• Add type hints to all function parameters and return values
• Document functions with ReStructuredText-style docstrings

Imports

• Group imports: standard library, third-party, local modules
• Import specific functions/classes rather than entire modules when practical

Error Handling

• Use assertions for validation
• Raise appropriate exceptions with informative messages
• Add context to exceptions when re-raising

Development Workflow

Before Pushing Code

1. Always run formatting tools: make format
   • This runs Black, isort, and linecheck
   • Fixes most formatting issues automatically
2. Check your formatting: make check-format
   • Ensures your code will pass CI linting checks
3. Run tests locally: make test
   • Catch test failures before CI
4. Check for trailing newlines: All files must end with a newline
   • The linecheck tool will catch this

Common CI Failures

• Linting failures: Run make format to fix
• Missing trailing newlines: Run make format or add manually
• Import order issues: Run isort microimpute/
• Line length issues: Run black microimpute/ --line-length 79

Code Integrity and Test Data Handling

• NEVER HARDCODE LOGIC JUST TO PASS SPECIFIC TEST CASES
  • This undermines code quality and model integrity
  • It creates technical debt and maintenance nightmares
  • It destroys the ability to trust results
  • Never add conditional logic that returns fixed values for specific input combinations