Polars vs. Pandas: What's the Difference?

If you've been keeping up with recent Python developments, you’ve probably heard of Polars, a new library for working with data. While pandas has been the goto library for a long time, Polars is making waves, especially for handling big datasets. So, what’s the big deal with Polars? How is it different from pandas? Let’s break it down.

What is Polars?

Polars is a free, open-source library built in Rust (a fast, modern programming language). It’s designed to help Python developers handle data in a faster, more efficient way. Think of it as an alternative to pandas one that shines when you're working with really large datasets that pandas might struggle with.

Why Was Polars Created?

Pandas has been around for years, and many people still love using it. But as data has gotten bigger and more complex, pandas has started to show some weaknesses. Ritchie Vink, the creator of Polars, noticed these issues and decided to create something faster and more efficient. Even Wes McKinney, the creator of pandas, admitted in a blog post titled "10 Things I Hate About pandas" that pandas could use some improvement, especially with large datasets.

That’s where Polars comes in it’s designed to be blazing fast and memory efficient, two things pandas struggles with when handling big data.

Key Differences: Polars vs. Pandas

1. Speed

Polars is really fast. In fact, some benchmarks show that Polars can be up to 5–10 times faster than pandas when performing common operations, like filtering or grouping data. This speed difference is especially noticeable when you’re working with large datasets.

2. Memory Usage

Polars is much more efficient when it comes to memory. It uses about 5 to 10 times less memory than pandas, which means you can work with much larger datasets without running into memory issues.

3. Lazy Execution

Polars uses something called lazy execution, which means it doesn’t immediately run each operation as you write it. Instead, it waits until you’ve written a series of operations, then runs them all at once. This helps it optimize and run things faster. Pandas, on the other hand, runs every operation immediately, which can be slower for big tasks.

4. Multithreading

Polars can use multiple CPU cores at the same time to process data, which makes it even faster for big datasets. Pandas is mostly single threaded, meaning it can only use one CPU core at a time, which slows things down, especially with large datasets.

Why is Polars So Fast?

Polars is fast for a couple of reasons:

• It’s built in Rust, a programming language known for its speed and safety, making it super efficient.
• It uses Apache Arrow, a special way of storing data in memory that makes it easier and faster to work with across different programming languages.

This combination of Rust and Apache Arrow gives Polars the edge over pandas when it comes to speed and memory use.

Strengths and Limitations of Pandas

While Polars is great for big data, pandas still has its place. Pandas works really well with small to medium-sized datasets and has been around for so long that it’s got tons of features and a huge community. So, if you’re not working with huge datasets, pandas might still be your best option.

However, as your datasets get larger, pandas tends to use more memory and gets slower, making Polars a better choice in those situations.

When Should You Use Polars?

You should consider using Polars if:

• You’re working with large datasets (millions or billions of rows).
• You need speed and performance to get your tasks done quickly.
• You have memory constraints and need to save on how much RAM you’re using.

Conclusion

Both Polars and pandas have their strengths. If you’re working with small to medium datasets, pandas is still a great tool. But if you’re dealing with large datasets and need something faster and more memory efficient, Polars is definitely worth trying out. Its performance boosts, thanks to Rust and Apache Arrow, make it a fantastic option for data-intensive tasks.

As Python continues to evolve, Polars might just become the new goto tool for handling big data.

Happy Coding 🐼 🐻