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Jupyter Core

Core common functionality of Jupyter projects.

This package contains base application classes and configuration inherited by other projects. It doesn't do much on its own.

Development Setup

The Jupyter Contributor Guides provide extensive information on contributing code or documentation to Jupyter projects. The limited instructions below for setting up a development environment are for your convenience.


You'll need Python and pip on the search path. Clone the Jupyter Core git repository to your computer, for example in /my/projects/jupyter_core. Now create an editable install and download the dependencies of code and test suite by executing:

cd /my/projects/jupyter_core/
pip install -e ".[test]"

The last command runs the test suite to verify the setup. During development, you can pass filenames to py.test, and it will execute only those tests.

Code Styling

jupyter_core has adopted automatic code formatting so you shouldn't need to worry too much about your code style. As long as your code is valid, the pre-commit hook should take care of how it should look. pre-commit and its associated hooks will automatically be installed when you run pip install -e ".[test]"

To install pre-commit manually, run the following:

    pip install pre-commit
    pre-commit install

You can invoke the pre-commit hook by hand at any time with:

    pre-commit run

which should run any autoformatting on your code and tell you about any errors it couldn't fix automatically. You may also install black integration into your text editor to format code automatically.

If you have already committed files before setting up the pre-commit hook with pre-commit install, you can fix everything up using pre-commit run --all-files. You need to make the fixing commit yourself after that.


The documentation of Jupyter Core is generated from the files in docs/ using Sphinx. Instructions for setting up Sphinx with a selection of optional modules are in the Documentation Guide. You'll also need the make command. For a minimal Sphinx installation to process the Jupyter Core docs, execute:

pip install sphinx

The following commands build the documentation in HTML format and check for broken links:

cd /my/projects/jupyter_core/docs/
make html linkcheck

Point your browser to the following URL to access the generated documentation: