Skip to main content

Write snippets of code in C++, Python, Ruby, and others as documentation and execute them as regression tests.

Project description

<!– Check that we have byexample installed first $ hash byexample # byexample: +fail-fast



byexample is a literate programming engine where you mix ordinary text and snippets of code in the same file and then you execute them as regression tests.

It lets you to execute the examples written in Python, Ruby or whatever in your documentation and validate them.

You can always be sure that the examples are correct and your documentation is up to date!


You write your documentation with examples in a Markdown or other text file.

Then, you run byexample from the command line selecting which language or languages you want to run: Python, Ruby, Shell and C/C++ to mention a few.

And yes, you can write examples in different languages in the same file. Combine them to combine their strengths and make your life easier.

That’s all. byexample will compare the output of the examples with the expected ones and it will show any difference.

How do I get started?

First, you need to install it:

$ pip install byexample                # install it # byexample: +skip

Or if you prefer, you can install it inside a virtual env.

If you don’t have pip or python installed, check the download page.

That’s it! Now, write a tutorial, a blog or a how-to and put some examples in between (like this that you are reading); All the snippets and examples will be collected, executed and checked.

$ byexample -l python,ruby,shell      # run it    # byexample: +skip
[PASS] Pass: <...> Fail: <...> Skip: <...>

Several languages are supported like Python, Ruby and C++ along with others.

Take at look at the official web page:

Some quick links:

Languages supported

Currently we support:

More languages will be supported in the future. Stay tuned.

Currently unsupported:

Help is needed!

Platforms supported

Linux is the preferable choice as it is very well tested.

Since 9.2.1 macOS is also supported for the testing is more limited and it is expected to have little variations from Linux.

You can even run byexample in Windows** using Windows Subsystem for Linux but keep in mind that the testing is even more limited; a native execution in Windows (outside of WSL) is currently not supported.


First off, thanks for using and considering contributing to byexample.

We love to receive contributions from our community. There are tons of ways you can contribute

  • add support to new languages (Javascript, Julia, just listen to you heart). Check this how to.
  • misspelling? Improve to the documentation is more than welcome.
  • add more examples. How do you use byexample? Give us your feedback!
  • is byexample producing a hard-to-debug diff or you found a bug? Create an issue in github.

But don’t be limited to those options. We keep our mind open to other useful contributions: write a tutorial or a blog, feature requests, social media…

Check out our CONTRIBUTING guidelines and welcome!

Extend byexample

It is possible to extend byexample adding new ways to find examples in a document and/or to parse and run/interpret a new language or adding hooks to be called regardless of the language/interpreter.

Check out how to support new finders and languages and how to hook to events with concerns for a quick tutorials that shows exactly how to do that.

You could also share your work and contribute to byexample with your extensions.


We use semantic version for the core or engine.

For each module we have the following categorization:

  • experimental: non backward compatibility changes are possible or even removal between versions (even patch versions).
  • provisional: low impact non backward compatibility changes may occur between versions; but in general a change like that will happen only between major versions.
  • stable: non backward compatibility changes, if happen, they will between major versions.
  • deprecated: it will disappear in a future version.
  • unsupported: it may work but currently it is not possible to offer any guarantees. Contributions from the community are needed!

See the latest releases and tags and the changelog

Current version:

$ byexample -V
byexample 10.5.6 (Python <...>) - GNU GPLv3
Copyright (C) Di Paola Martin -


This project is licensed under GPLv3

$ head -n 2 LICENSE     # byexample: +norm-ws
           Version 3, 29 June 2007

See LICENSE for more details.

Download files

Download the file for your platform. If you're not sure which to choose, learn more about installing packages.

Source Distribution

byexample-10.5.6.tar.gz (129.9 kB view hashes)

Uploaded source

Built Distribution

byexample-10.5.6-py3-none-any.whl (164.6 kB view hashes)

Uploaded py3

Supported by

AWS AWS Cloud computing Datadog Datadog Monitoring Facebook / Instagram Facebook / Instagram PSF Sponsor Fastly Fastly CDN Google Google Object Storage and Download Analytics Huawei Huawei PSF Sponsor Microsoft Microsoft PSF Sponsor NVIDIA NVIDIA PSF Sponsor Pingdom Pingdom Monitoring Salesforce Salesforce PSF Sponsor Sentry Sentry Error logging StatusPage StatusPage Status page