polars

Process tabular data with Polars in Python using lazy evaluation and expressions.

Updated Jan 14, 2026
One-click install
npx skills add https://github.com/oornnery/skills --skill polars-oornnery
Or copy as Structured Prompt for Agent
Please help me install this Agent Skill.
Skill: polars
Source: https://github.com/oornnery/skills/tree/main/skills/polars
Command: npx skills add https://github.com/oornnery/skills --skill polars-oornnery

SYSTEM DOCUMENTATION & REQUIREMENTS

💡 This Skill includes assets (resource) and references (resource) components.

What problem does it solve?

Polars enables fast, memory-efficient dataframe processing in Python, allowing scalable analysis and transformation of large tabular datasets with expressive APIs.

Core Features & Use Cases

  • Expression-first data pipelines with lazy evaluation for performance and scalability
  • Fast IO for CSV, Parquet, and NDJSON, plus efficient joins, aggregations, and window functions
  • Practical guidance for migrating from pandas and building reliable data analytics workflows

Quick Start

Run assets/main.py to execute the sample Polars pipeline and generate report.parquet

Frequently Asked Questions about polars

High-intent search queries and answers about installing and using this skill.

FAQPage Schema
How do I process large tabular datasets efficiently in Python?

To process large tabular datasets efficiently in Python, use Polars for fast, memory-efficient dataframe operations. It enables scalable analysis and transformation through expression-first pipelines with lazy evaluation.

What is lazy evaluation and how does it optimize dataframe workflows?

Lazy evaluation in dataframe workflows optimizes performance by deferring execution until the entire plan is built. Polars uses this approach to optimize scalability, allowing the engine to reorder operations and reduce memory usage.

How do I read CSV, Parquet, and NDJSON files for data transformation?

Read CSV, Parquet, and NDJSON files for data transformation using Polars fast IO capabilities. This allows you to quickly load moderate to large datasets for subsequent joins, aggregations, and window functions.

Does this approach work for migrating existing pandas pipelines?

Yes, this approach works for migrating existing pandas pipelines. The framework provides practical guidance for transitioning from pandas to build reliable, performance-conscious data analytics workflows using explicit typing and expressions.

What's the best way to build scalable ETL pipelines with Python dataframes?

The best way to build scalable ETL pipelines with Python dataframes is using an expression-first library like Polars. It emphasizes lazy versus eager planning and explicit typing to handle moderate to large datasets memory-efficiently.

Do I need prior Python experience to use these dataframe expressions?

Yes, you need prior Python experience to use these dataframe expressions. The framework requires familiarity with Python and Polars to effectively utilize lazy evaluation, expressions, and performance-conscious patterns.