nodejs-polars

Polars

Polars: Blazingly fast DataFrames in Rust, Python, Node.js, R and SQL

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Documentation: Node.js - Rust - Python - R |StackOverflow: Node.js - Rust - Python | User Guide | Discord

// esm
import pl from 'nodejs-polars';

// require
const pl = require('nodejs-polars');
> const fooSeries = pl.Series("foo", [1, 2, 3])
> fooSeries.sum()
6

// a lot operations support both positional and named arguments
// you can see the full specs in the docs or the type definitions
> fooSeries.sort(true)
> fooSeries.sort({reverse: true})
shape: (3,)
Series: 'foo' [f64]
[
3
2
1
]
> fooSeries.toArray()
[1, 2, 3]

// Series are 'Iterables' so you can use javascript iterable syntax on them
> [...fooSeries]
[1, 2, 3]

> fooSeries[0]
1
>const df = pl.DataFrame(
... {
... A: [1, 2, 3, 4, 5],
... fruits: ["banana", "banana", "apple", "apple", "banana"],
... B: [5, 4, 3, 2, 1],
... cars: ["beetle", "audi", "beetle", "beetle", "beetle"],
... }
... )
> df.sort("fruits").select(
... "fruits",
... "cars",
... pl.lit("fruits").alias("literal_string_fruits"),
... pl.col("B").filter(pl.col("cars").eq(pl.lit("beetle"))).sum(),
... pl.col("A").filter(pl.col("B").gt(2)).sum().over("cars").alias("sum_A_by_cars"),
... pl.col("A").sum().over("fruits").alias("sum_A_by_fruits"),
... pl.col("A").reverse().over("fruits").flatten().alias("rev_A_by_fruits")
... )
shape: (5, 8)
┌──────────┬──────────┬──────────────┬─────┬─────────────┬─────────────┬─────────────┐
fruitscarsliteral_striBsum_A_by_casum_A_by_frrev_A_by_fr
│ --- ┆ --- ┆ ng_fruits ┆ --- ┆ rsuitsuits
strstr ┆ --- ┆ i64 ┆ --- ┆ --- ┆ --- │
│ ┆ ┆ str ┆ ┆ i64i64i64
╞══════════╪══════════╪══════════════╪═════╪═════════════╪═════════════╪═════════════╡
"apple""beetle""fruits"11474
├╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌┤
"apple""beetle""fruits"11473
├╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌┤
"banana""beetle""fruits"11485
├╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌┤
"banana""audi""fruits"11282
├╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌┤
"banana""beetle""fruits"11481
└──────────┴──────────┴──────────────┴─────┴─────────────┴─────────────┴─────────────┘
> df["cars"] // or df.getColumn("cars")
shape: (5,)
Series: 'cars' [str]
[
"beetle"
"beetle"
"beetle"
"audi"
"beetle"
]

Install the latest polars version with:

$ yarn add nodejs-polars # yarn
$ npm i -s nodejs-polars # npm

Releases happen quite often (weekly / every few days) at the moment, so updating polars regularly to get the latest bugfixes / features might not be a bad idea.

  • Node version >=18
  • Rust version >=1.59 - Only needed for development

In Deno modules you can import polars straight from npm:

import pl from "npm:nodejs-polars";

With Deno 1.37, you can use the display function to display a DataFrame in the notebook:

import pl from "npm:nodejs-polars";
import { display } from "https://deno.land/x/display@v1.1.1/mod.ts";

let response = await fetch(
"https://cdn.jsdelivr.net/npm/world-atlas@1/world/110m.tsv",
);
let data = await response.text();
let df = pl.readCSV(data, { sep: "\t" });
await display(df)

With Deno 1.38, you only have to make the dataframe be the last expression in the cell:

import pl from "npm:nodejs-polars";
let response = await fetch(
"https://cdn.jsdelivr.net/npm/world-atlas@1/world/110m.tsv",
);
let data = await response.text();
let df = pl.readCSV(data, { sep: "\t" });
df
image

Want to know about all the features Polars supports? Read the docs!

Want to contribute? Read our contribution guideline.

If you want a bleeding edge release or maximal performance you should compile polars from source.

  1. Install the latest Rust compiler
  2. Run npm|yarn install
  3. Choose any of:
    • Fastest binary, very long compile times:
      $ cd nodejs-polars && yarn build && yarn build:ts # this will generate a /bin directory with the compiles TS code, as well as the rust binary
      
    • Debugging, fastest compile times but slow & large binary:
      $ cd nodejs-polars && yarn build:debug && yarn build:ts # this will generate a /bin directory with the compiles TS code, as well as the rust binary
      

To use nodejs-polars with Webpack please use node-loader and webpack.config.js

Development of Polars is proudly powered by

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