The Ultimate Combo: Using SQL on Polars DataFrames with DuckDB
You love Polars for its speed, but sometimes you just miss writing SQL. Maybe a colleague gave you a complex query and you don’t want…
Polars vs. Pandas: Zero-Copy Conversion (The Arrow Revolution)
One of the biggest fears about switching to a new tool like Polars is: “What if I need a library that only works with Pandas?”…
Writing Data in Polars: write_csv, write_json, write_parquet
You’ve read, cleaned, and analyzed your data in Polars. Now you need to save your results. If you’ve ever wondered how Polars write data when…
How to Fix: MemoryError in Python
A MemoryError is one of Python’s most serious errors. If you’ve encountered a MemoryError Python problem before, you know it’s not a syntax issue; it’s…
Polars vs. Pandas: A 1GB Performance Showdown (2026 Guide)
We’ve told you Polars is faster than Pandas. When it comes to Polars vs Pandas Performance, now let’s prove it. We’ll create a 1GB (10…
Polars Project: A-to-Z Time-Series Analysis (Resampling & Moving Averages)
This “capstone” project combines all the Polars time-series skills you’ve learned. In this exercise, you’ll put Polars Time-Series Analysis techniques into practice. Goal: Take noisy,…
How to Read JSON Files in Polars (read_json)
You’ve learned to read CSVs, Parquet, and Excel. But many APIs and modern databases (like MongoDB) output JSON files. In this tutorial, you’ll learn how…
Using Regex in Polars: .str.contains(), .str.replace_all(), .str.extract()
In our Polars string guide, we covered basic text cleaning. When your data demands pattern-level precision, Polars regex delivers — it builds Regular Expression (Regex)…
How to Apply Custom Functions on Polars Groups (.group_by().apply())
We know that .map_elements() is slow because it runs row-by-row. We know that .group_by().agg() is super fast, but it’s limited to simple functions (like sum,…
Polars Window Functions: shift() and rank() Explained
Today we’re covering two powerful Polars Expressions: shift and rank. These are essential for financial analysis, ranking, and finding trends. In this article you’ll learn…
