October 21, 2019

711 words 4 mins read



Easy to use test framework for Jupyter Notebooks

repo name ReviewNB/treon
repo link https://github.com/ReviewNB/treon
homepage https://reviewnb.com
language Python
size (curr.) 87 kB
stars (curr.) 223
created 2019-03-29
license MIT License


PyPI version Build Status

Easy to use test framework for Jupyter Notebooks.

  • Runs notebook top to bottom and flags execution errors if any
  • Runs unittest present in your notebook code cells
  • Runs doctest present in your notebook code cells

Why should you use it?

  • Start testing notebooks without writing a single line of test code
  • Multithreaded execution for quickly testing a set of notebooks
  • Executes every Notebook in a fresh kernel to avoid hidden state problems
  • Primarily a command line tool that can be used easily in any Continuous Integration (CI) system
  • Soon to be part of ReviewNB’s CI system that automatically runs treon everytime you push notebook changes to GitHub


pip install treon


$ treon
Executing treon version 0.1.0
Recursively scanning /workspace/treon/tmp/docs/site/ru/guide for Notebooks...

Collected following Notebooks for testing

Triggered test for /workspace/treon/tmp/docs/site/ru/guide/keras.ipynb
Triggered test for /workspace/treon/tmp/docs/site/ru/guide/eager.ipynb

test_sum (__main__.TestNotebook) ...
test_sum (__main__.TestNotebook2) ...
test_sum (__main__.TestNotebook3) ...

Ran 3 tests in 0.004s


/workspace/treon/tmp/docs/site/ru/guide/keras.ipynb       -- PASSED
/workspace/treon/tmp/docs/site/ru/guide/eager.ipynb       -- PASSED
2 succeeded, 0 failed, out of 2 notebooks tested.

Command line arguments

  treon [PATH] [--threads=<number>] [-v] [--exclude=<string>]...

  PATH                File or directory path to find notebooks to test. Searches recursively for directory paths. [default: current working directory]

  --threads=<number>  Number of parallel threads. Each thread processes one notebook file at a time. [default: 10]
  -e=<string> --exclude=<string>  Option for excluding files or entire directories from testing. All files whose
                      absolute path starts with the specified string are excluded from testing. This option can be
                      specified more than once to exclude multiple files or directories. If the exclude path is
                      a valid directory name, only this directory is excluded.
  -v --verbose        Print detailed output for debugging.
  -h --help           Show this screen.
  --version           Show version.

unitttest example

You just need to add tests as shown below & treon would execute them and report the result on the console. See this for more details on how to write unittest.

doctest example

You just need to add tests as shown below & treon would execute them and report the result on the console. See this for more details on how to write doctest.

Note about dependencies

  • You need to run treon from environment (virtualenv/pipenv etc.) that has all the dependcies required for Notebooks under test
  • treon only works with python3+ environments and uses python3 kernel for executing notebooks


For development, you may use below to create a Python interpreter that resides in venv in the current working directory, and to install all of treon’s dependencies:

$ virtualenv venv
$ source venv/bin/activate
$ pip install -e .
$ pip install -r requirements-dev.txt
$ treon --help # should work

Because the script installs the package as editable, you can make changes in the source tree and use the treon command to immediately validate them. If this does not appear to work, check that you are using a the proper virtual environment, and that the package is indeed installed in editable mode:

$ which treon # should point into your virtualenv
$ pip list --local | grep treon # should point to the source tree
treon                0.1.3                /workspace/treon

Please refer to the Makefile for supplementary development tasks. In particular, the following targets may be relevant when validating changes before committing:

$ make lint # check treon's source for code style errors
$ make test # run all tests


Our aim at ReviewNB is to make notebooks a first class entity in the production workflow. We’ve built a code review system for Notebooks. The next step is to build a CI pipeline & treon is the core tool in that effort. It is licensed librerally (MIT) & I foresee it being used as an independent tool as well. You can use it locally and/or integrate with CI system of your choice.

For motivation, checkout Netflix’s blog to see how notebooks are graduating from scratchpad to a part of production workflow.


If you see any problem, open an issue or send a pull request. You can write to team@reviewnb.com for any questions.

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