Polars CLI

The Polars command line interface provides a convenient way to execute SQL commands using Polars as a backend.

Installation

The recommended way to install the Polars CLI is by using pip:

pip install polars-cli

This will install a pre-compiled binary and make it available on your path under polars. If you do not have Python available, you can download a suitable binary from the most recent GitHub release.

Alternatively, you can install the Polars CLI using cargo, which will compile the code from scratch:

cargo install --locked polars-cli

Usage

Running polars without any arguments will start an interactive shell in which you can run SQL commands.

$ polars
Polars CLI version 0.4.0
Type .help for help.

>> select * FROM read_csv('examples/datasets/foods.csv');
┌────────────┬──────────┬────────┬──────────┐
│ category   ┆ calories ┆ fats_g ┆ sugars_g │
│ ---        ┆ ---      ┆ ---    ┆ ---      │
│ str        ┆ i64      ┆ f64    ┆ i64      │
╞════════════╪══════════╪════════╪══════════╡
│ vegetables ┆ 45       ┆ 0.5    ┆ 2        │
│ seafood    ┆ 150      ┆ 5.0    ┆ 0        │
│ meat       ┆ 100      ┆ 5.0    ┆ 0        │
│ fruit      ┆ 60       ┆ 0.0    ┆ 11       │
│ …          ┆ …        ┆ …      ┆ …        │
│ seafood    ┆ 200      ┆ 10.0   ┆ 0        │
│ seafood    ┆ 200      ┆ 7.0    ┆ 2        │
│ fruit      ┆ 60       ┆ 0.0    ┆ 11       │
│ meat       ┆ 110      ┆ 7.0    ┆ 0        │
└────────────┴──────────┴────────┴──────────┘

Alternatively, SQL commands can be piped directly into the Polars CLI.

$ echo "SELECT category FROM read_csv('examples/datasets/foods.csv')" | polars
┌────────────┐
│ category   │
│ ---        │
│ str        │
╞════════════╡
│ vegetables │
│ seafood    │
│ meat       │
│ fruit      │
│ …          │
│ seafood    │
│ seafood    │
│ fruit      │
│ meat       │
└────────────┘

Features

When compiling the Polars CLI from source, the following features can be enabled:

Feature	Description
default	The default feature set that includes all other features.
highlight	Provides syntax highlighting
parquet	Enables reading and writing of Apache Parquet files.
json	Enables reading and writing of JSON files.
ipc	Enables reading and writing of IPC/Apache Arrow files