Customizing Jupyter Notebook Themes: Switching to a Dark Theme

Introduction

Jupyter Notebooks are an incredibly popular tool for data analysis, machine learning, and educational purposes. They combine live code execution with rich text elements like equations, visualizations, and narrative text. The default theme in Jupyter Notebooks is light, which may not be suitable for everyone’s preferences or working environments. This tutorial will guide you through customizing your Jupyter Notebook interface by changing its theme to a dark one, enhancing readability and reducing eye strain.

Understanding Themes in Jupyter

Themes control the aesthetic aspects of the Jupyter Notebook interface, such as colors, fonts, and layout. A "dark" theme typically involves using darker backgrounds with lighter text, which is preferred by many users for comfort during extended use or in low-light conditions.

Changing the Theme Using `jupyterthemes`

To change themes in Jupyter Notebooks, we’ll use a popular tool called jupyterthemes. This Python package offers various customization options and supports multiple themes. Here’s how you can install and apply it:

Installation

Firstly, ensure that you have either conda or pip installed on your system to manage packages.

Using conda:

conda install -c conda-forge jupyterthemes

Using pip:
```
pip install jupyterthemes
```

Applying a Theme

Once jupyterthemes is installed, you can list and apply available themes using the following commands:

List Available Themes

To see all available themes:
```
jt -l
```
Some popular dark themes include:
- onedork
- monokai
- solarizedd
Apply a Theme

Choose your preferred theme and apply it using:
```
jt -t <theme-name>
```
For example, to set the monokai theme:
```
jt -t monokai
```
Customization Options

Optionally, you can retain the toolbar by adding -T or --toolbar in your command:
```
jt -t <theme-name> -T
```
Refresh Your Notebook

After applying a new theme, refresh the Jupyter Notebook page to see changes.

Reverting to Default Theme

If you decide to revert back to the default light theme, use:

jt -r

Restart your Jupyter server initially and then simply refresh for subsequent reversion.

Alternative Method: Using Browser Extensions

For those who prefer not to install additional Python packages, browser extensions like "Dark Reader" can provide a quick solution. Here’s how you can do it:

Install Dark Reader Extension

Available on browsers such as Chrome and Firefox, this extension allows for dynamic theme adjustments without altering the server-side configuration.
Customize Your Theme

After installation, configure settings to adjust contrast, brightness, or apply a custom CSS filter for your desired dark mode effect.

Best Practices

Backup Configuration: Before applying any changes, it’s wise to back up your current Jupyter Notebook settings.
Experiment with Themes: Feel free to test different themes and configurations until you find the one that suits your needs best.
Use Extensions Responsibly: While browser extensions are convenient, ensure they do not interfere with other web functionalities within Jupyter Notebooks.

Conclusion

Customizing your Jupyter Notebook theme can significantly enhance your coding experience by making it more visually appealing and comfortable for long sessions. Whether you choose to use jupyterthemes or a browser extension like "Dark Reader," both methods provide flexibility and control over the appearance of your notebooks. Experiment with different settings to discover what works best for you.