Getting Started

NB: This is nbdev v2, a major upgrade of nbdev. Whilst the differences to nbdev1 aren’t huge, it does require some changes. The old version docs are at nbdev1.fast.ai. You can use version-pinning in settings.ini (i.e 'nbdev<2') to stop nbdev from upgrading. To upgrade, follow the migration tutorial.

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nbdev is a notebook-driven development platform. Simply write notebooks with lightweight markup and get high-quality documentation, tests, continuous integration, and packaging for free!

nbdev makes debugging and refactoring your code much easier than in traditional programming environments since you always have live objects at your fingertips. nbdev also promotes software engineering best practices because tests and documentation are first class.

• Documentation is automatically generated using Quarto and hosted on GitHub Pages. Docs support LaTeX, are searchable, and are automatically hyperlinked (including out-of-the-box support for many packages via nbdev-index)
• Publish packages to PyPI and conda as well as tools to simplify package releases. Python best practices are automatically followed, for example, only exported objects are included in __all__
• Two-way sync between notebooks and plaintext source code allowing you to use your IDE for code navigation or quick edits
• Tests written as ordinary notebook cells are run in parallel with a single command
• Continuous integration out-of-the-box with GitHub Actions that run your tests and rebuild your docs
• Git-friendly notebooks with Jupyter/Git hooks that clean unwanted metadata and render merge conflicts in a human-readable format
• … and much more!

Install

nbdev works on macOS, Linux, and most Unix-style operating systems. It works on Windows under WSL, but not under cmd or Powershell.

You can install nbdev with pip:

pip install nbdev

… or with conda (or mamba):

conda install -c fastai nbdev

Note that nbdev must be installed into the same Python environment that you use for both Jupyter and your project.

How to use nbdev

The best way to learn how to use nbdev is to complete either the written walkthrough or video walkthrough:

Alternatively, there’s a shortened version of the video walkthrough with coding sections sped up using the unsilence Python library – it’s 27 minutes faster, but a bit harder to follow.

You can also run nbdev_help from the terminal to see the full list of available commands:

!nbdev_help

nbdev_bump_version              Increment version in settings.ini by one
nbdev_changelog                 Create a CHANGELOG.md file from closed and labeled GitHub issues
nbdev_clean                     Clean all notebooks in `fname` to avoid merge conflicts
nbdev_conda                     Create a `meta.yaml` file ready to be built into a package, and optionally build and upload it
nbdev_create_config             Create a config file.
nbdev_deploy                    Deploy docs to GitHub Pages
nbdev_docs                      Create Quarto docs and README.md
nbdev_export                    Export notebooks in `path` to Python modules
nbdev_filter                    A notebook filter for Quarto
nbdev_fix                       Create working notebook from conflicted notebook `nbname`
nbdev_help                      Show help for all console scripts
nbdev_install                   Install Quarto and the current library
nbdev_install_hooks             Install Jupyter and git hooks to automatically clean, trust, and fix merge conflicts in notebooks
nbdev_install_quarto            Install latest Quarto on macOS or Linux, prints instructions for Windows
nbdev_merge                     Git merge driver for notebooks
nbdev_migrate                   Convert all directives and callouts in `fname` from v1 to v2
nbdev_new                       Create an nbdev project.
nbdev_prepare                   Export, test, and clean notebooks, and render README if needed
nbdev_preview                   Preview docs locally
nbdev_proc_nbs                  Process notebooks in `path` for docs rendering
nbdev_pypi                      Create and upload Python package to PyPI
nbdev_readme                    None
nbdev_release_both              Release both conda and PyPI packages
nbdev_release_gh                Calls `nbdev_changelog`, lets you edit the result, then pushes to git and calls `nbdev_release_git`
nbdev_release_git               Tag and create a release in GitHub for the current version
nbdev_sidebar                   Create sidebar.yml
nbdev_test                      Test in parallel notebooks matching `path`, passing along `flags`
nbdev_trust                     Trust notebooks matching `fname`
nbdev_update                    Propagate change in modules matching `fname` to notebooks that created them

FAQ

Q: What is the warning “Found a cell containing mix of imports and computations. Please use separate cells”?

A: You should not have cells that are not exported, and contain a mix of import statements along with other code. For instance, don’t do this in a single cell:

import some_module
some_module.something()

Instead, split this into two cells, one which does import some_module, and the other which does some_module.something().

The reason for this is that when we create your documentation website, we ensure that all of the signatures for functions you document are up to date, by running the imports, exported cells, and show_doc functions in your notebooks. When you mix imports with other code, that other code will be run too, which can cause errors (or at least slowdowns) when creating your website.

Q: Why is nbdev asking for root access? How do I install Quarto without root access?

A: When you setup your first project, nbdev will attempt to automatically download and install Quarto for you. This is the program that we use to create your documentation website.

Quarto’s standard installation process requires root access, and nbdev will therefore ask for your root password during installation. For most people, this will work fine and everything will be handled automatically – if so, you can skip over the rest of this section, which talks about installing without root access.

If you need to install Quarto without root access on Linux, first cd to wherever you want to store it, then download Quarto, and type:

dpkg -x quarto*.deb .
mv opt/quarto ./
rmdir opt
mkdir -p ~/.local/bin
ln -s "$(pwd)"/quarto/bin/quarto ~/.local/bin

To use this non-root version of Quarto, you’ll need ~/.local/bin in your PATH environment variable. (Alternatively, change the ln -s step to place the symlink somewhere else in your path.)

Q: Someone told me not to use notebooks for “serious” software development!

A: Watch this video. Don’t worry, we still get this too, despite having used nbdev for a wide range of “very serious” software projects over the last three years, including deep learning libraries, API clients, Python language extensions, terminal user interfaces, and more!

Contributing

If you want to contribute to nbdev, be sure to review the contributions guidelines. This project adheres to fastai’s code of conduct. By participating, you are expected to uphold this code. In general, we strive to abide by generally accepted best practices in open-source software development.

Make sure you have nbdev’s git hooks installed by running nbdev_install_hooks in the cloned repository.

Copyright

Copyright © 2019 onward fast.ai, Inc. Licensed under the Apache License, Version 2.0 (the “License”); you may not use this project’s files except in compliance with the License. A copy of the License is provided in the LICENSE file in this repository.