testbook is a unit testing framework extension for testing code in Jupyter Notebooks.

Previous attempts at unit testing notebooks involved writing the tests in the notebook itself. However, testbook will allow for unit tests to be run against notebooks in separate test files, hence treating .ipynb files as .py files.

testbook helps you set up conventional unit tests for your Jupyter Notebooks.

Here is an example of a unit test written using testbook

Consider the following code cell in a Jupyter Notebook example_notebook.ipynb:

def func(a, b):
   return a + b

You would write a unit test using testbook in a Python file example_test.py as follows:

# example_test.py
from testbook import testbook


@testbook('/path/to/example_notebook.ipynb', execute=True)
def test_func(tb):
   func = tb.get("func")

   assert func(1, 2) == 3

Then pytest can be used to run the test:

pytest example_test.py

pip install testbook

NOTE: This does not install any kernels for running your notebooks. You'll need to install in the same way you do for running the notebooks normally. Usually this is done with pip install ipykernel

Alternatively if you want all the same dev dependencies and the ipython kernel you can install these dependencies with:

pip install testbook[dev]

See readthedocs for more in-depth details.

Read CONTRIBUTING.md for guidelines on how to setup a local development environment and make code changes back to testbook.