What problem does it solve?
Polars eliminates slow, single-threaded DataFrame operations by providing a high-performance, parallel, Apache Arrow-backed in-memory engine so users can process and transform large datasets that fit in RAM with predictable typing and faster execution than pandas.
Core Features & Use Cases
- High performance: Lazy evaluation, expression-based API, and parallel execution minimize runtime for ETL and analytics pipelines.
- Flexible I/O: Efficient scanning and reading/writing for CSV, Parquet, JSON, Excel and cloud storage with predicate and projection pushdown.
- Advanced transformations: Group-by aggregations, window functions, joins, pivots, concatenation, streaming collection, and memory-efficient type casting for datasets in the 1–100GB range.
- Use Case: Migrate pandas pipelines to Polars to speed up nightly aggregations, join large tables for reporting, or perform feature engineering for machine learning workloads.
Quick Start
Scan the input file lazily, filter rows where age is greater than 25, select the name and age columns, and collect the result into memory.