The PyArrow revolution in Pandas — Reuven M. Lerner

Explore how PyArrow revolutionizes Pandas with 5x faster operations, reduced memory usage, and better data handling. Learn about new file formats and future integration plans.

Key takeaways
  • PyArrow offers significant performance improvements over traditional Pandas/NumPy backend, with 5x faster CSV reading and up to 80% reduced memory usage

  • PyArrow introduces nullable integer types that handle NaN values without forcing conversion to floats, solving a common Pandas limitation

  • New file formats Feather and Parquet provide faster read/write operations and better compression compared to CSV files

    • Feather is faster but uncompressed
    • Parquet is slower but highly compressed
  • Column-based storage in PyArrow (vs row-based in traditional Pandas) enables faster data analysis operations, though row operations become slower

  • PyArrow provides better type inference and handling of dates, strings, and complex data types out of the box

  • While PyArrow is generally faster, it’s not always the case - especially for row operations and certain string operations which can be 30% slower

  • PyArrow integration is becoming a core part of Pandas’ future, with plans to make it the default backend in Pandas 3.0

  • Workflow recommendation: Load data once with PyArrow, save to Parquet/Feather format for subsequent faster access

  • PyArrow enables better interoperability between different data analysis tools and languages

  • Current limitations include experimental status of some features and potential issues with custom Python classes or complex data structures