fastparquet implements the Apache Parquet columnar storage format in Python for high-performance reading and writing of Parquet files. Inspired by parquet-python, the library supports a wide range of Parquet features, including nested data, row groups, and multiple compression codecs, and offers competitive I/O performance in a small dependency footprint. It integrates with NumPy and pandas to read and write DataFrames, and is used implicitly by higher-level projects such as Dask and intake-parquet for parallel, distributed data processing workflows. As of March 2026, the code is no longer being developed.