Welcome to polars-hist-db’s documentation!

Contents

polars-hist-db

This library is for scraping data from CSV style files, temporally, into MariaDB.

Main features are:

  • Uploading data from strongly-typed Polars DataFrames.

  • Querying data into Polars DataFrames, with column types inferred from the database schema.

  • A scrape specification that:

    • Defines pipelines for typing, enriching, and normalizing data before uploading.

    • Allows construction of the ‘as-of’ time from file attributes or as a function of the input columns.

    • Catalogs the history of scrape inputs to prevent duplication.

    • Supports per-file transactional scraping (either the processing for a file succeeds, or the transaction is rolled back).

Development Setup

  1. Create a virtual environment:

python3 -m venv .venv
source .venv/bin/activate

  1. Install development dependencies:

poetry install --with dev

  1. Run tests:

poetry run pytest

  1. Make docs. The documentation will be generated in the docs/_build/html directory:

cd docs && poetry run make html

Code Style

This project follows the following code style guidelines:

  • Use type hints for all function parameters and return values

  • Follow PEP 8 style guide

  • Use Google-style docstrings

  • Keep functions focused and single-purpose

  • Write comprehensive tests for new features

Run make check to check the code style.

Contributing

  1. Fork the repository

  2. Create a feature branch

  3. Commit your changes

  4. Push to the branch

  5. Create a Pull Request

License

This project is licensed under the terms specified in the LICENSE file.

References

Indices and tables