Ruff: The Extensible Python Linter
Tags: python, programming, linter
Published: 2024-05-07 08:08:45

[Ruff](https://github.com/astral-sh/ruff) is an open-source Python linter created by Astral Sh that stands out for its impressive speed, adaptability, and wide-ranging features.

This powerful tool has gained popularity among Python developers for its ability to streamline the code linting process.

By focusing on extensibility, fast performance, comprehensive linting rules, and easy configuration, Ruff aims to provide an efficient and user-friendly linting experience that can be tailored to various projects and coding styles.

---


## Key Features
Ruff is extremely actively developed and used in major open-source projects due to its impressive features.

Here are some of the key features:

- **Extensible**: Ruff is designed to be easily extended, so developers can add their own custom plugins, making it adaptable to various projects and coding styles.
- **Faster**: Ruff is built to be much faster than other Python linters, using Rust's performance and Python's user-friendliness to ensure quick and efficient code analysis, especially for large codebases.
- **Comprehensive**: Ruff supports many linting rules from popular tools like flake8, Pycodestyle, Pyflakes, and McCabe. It also offers auto-fixing for a wide range of issues, helping developers keep their code clean and consistent.
- **Easy Configuration**: Ruff's configuration is simple and intuitive, allowing developers to customize its behavior to fit their preferences and project needs.

---

## Benefits 
Ruff can be employed to replace [Flake8](https://pypi.org/project/flake8/) (along with numerous plugins). It does this while running much faster, sometimes even hundreds of times faster than any single tool.

Here are the key benefits:

- **Better Code Quality**: Ruff assists developers in maintaining consistent coding styles and spotting potential problems early on, resulting in higher-quality code with fewer errors.
- **Greater Productivity**: Ruff's fast performance and automatic issue-fixing features enable developers to concentrate on writing code, rather than wasting time manually fixing linting issues.
- **Easy Integration**: Ruff can be effortlessly combined with popular development tools and continuous integration systems, making it hassle-free to include linting in existing workflows.

---

## Getting Started with Ruff
To start using Ruff, first install it using pip:

```
pip install ruff
```

Next, run Ruff on your Python project:

```
ruff check .
```


Ruff will automatically analyze your code and report any linting issues it finds.

Here is an example of the output:

```
main.py:12:28: F401 [*] `youtube_client.upload_video` imported but unused
main.py:17:5: F841 Local variable `audio_folder` is assigned to but never used
main.py:23:5: F841 Local variable `credentials` is assigned to but never used
video_shorts.py:1:8: F401 [*] `os` imported but unused
video_shorts.py:2:22: F401 [*] `textwrap.fill` imported but unused
Found 5 errors.
[*] 3 fixable with the `--fix` option (2 hidden fixes can be enabled with the `--unsafe-fixes` option).
```

Errors can automatically be fixed by running:

```
ruff check . --fix
```

Which produces this output:

```
main.py:16:5: F841 Local variable `audio_folder` is assigned to but never used
main.py:22:5: F841 Local variable `credentials` is assigned to but never used
Found 5 errors (3 fixed, 2 remaining).
No fixes available (2 hidden fixes can be enabled with the `--unsafe-fixes` option).
```

As you can see, the remaining errors can be fixed with the unsafe-fixes option.

To configure Ruff, create a pyproject.toml file in your project's root directory and customize the settings according to your needs.

For example, to set the maximum line length to 100 characters and disable the undefined-name check, use the following configuration:

```
[tool.ruff]
line-length = 100
ignore = ["F821"]
```


---

## Conclusion
Ruff is an impressive and adaptable tool for checking Python code, offering quick performance, a wide range of linting rules, and straightforward configuration options. 

By using Ruff in their development workflows, Python developers can experience better code quality through consistent coding styles, early issue detection, and reduced bugs.

They can also improve productivity by focusing on writing code instead of manually addressing linting issues, and benefit from seamless integration with popular development tools and continuous integration systems.