Refactoring, add Docstrings and Type Hints to preprocessing files

[blue442]

Find opportunities to enhance the codebase by adding comprehensive docstrings and type hints to improve code readability, maintainability, and developer onboarding. This will also help with static type checking and tooling integrations (e.g., mypy, IDE autocompletion).

Given that this file is currently run as a script, it makes sense to perform some basic refactoring of the code in this file to utilize functions that will allow us to break up and compartmentalize the logic into smaller chunks. This is generally good practices as it allows much more precise debugging when things go wrong, and makes it much easier to navigate and adjust the codebase for future needs.

Target Files

• food_access_model/preprocessing/get_data.py

Rationale

• Improved Readability: Clear explanations for each function, class, and module help both new and experienced contributors understand the purpose and usage.
• Enhanced Maintainability: Well-documented code is easier to update and debug, reducing the learning curve for future enhancements.
• Type Safety: Incorporating type hints allows us to catch potential bugs early by leveraging static analysis tools.
• Tooling Support: Better documentation can improve the experience with code navigation and autocompletion in modern IDEs.

Proposed Changes

• Docstrings:
  • Add PEP 257 compliant docstrings to all public modules, classes, and functions.
  • Provide usage examples where applicable.
• Type Hints:
  • Annotate function parameters, return types, and class attributes according to PEP 484.
  • Review and update any ambiguous type annotations for clarity.

Steps to Implement

Refactoring

• Identify logical sections: Break the code into input, processing, logic, and output.
• Define functions: Create clear, reusable functions for each section.
• Avoid global variables: Use parameters and return values to pass data.
• Add a main() function: Organize the script’s flow in a central entry point.
• Implement error handling: Use try/except blocks where needed.

Docstrings

• Audit: Identify modules on the target files that lack proper docstrings and type hints.
• Documentation: Define a standard format for docstrings (e.g., Google style, NumPy style, or reStructuredText) and decide on a strategy for type hints.
• Implementation: Incrementally add docstrings and type hints, starting with core modules.
• Review: Use code reviews and static type checkers (like mypy) to ensure consistency and correctness.
• Testing: Run existing tests to confirm that changes haven’t introduced regressions.

Resources

• TH and DS: https://machinelearningmastery.com/comments-docstrings-and-type-hints-in-python-code/
• TH: https://dagster.io/blog/python-type-hinting