Refactor Python code for clarity, performance, and Pythonic idioms.

## Steps


1. Read the target Python file or module.
2. Identify refactoring opportunities:
3. Apply Pythonic improvements:
4. Improve code structure:
5. Improve error handling:
6. Run the tests to verify behavior is unchanged.
7. Run linting tools (ruff, flake8) to verify style compliance.

## Format


```
File: <path>
Refactorings Applied:
  - <pattern replaced> -> <Pythonic alternative>
Lines Changed: <before> -> <after>
```


## Rules

- Never change behavior during refactoring.
- Run tests after every refactoring step.
- Follow PEP 8 style guidelines.