![[old] Flatten a List](https://dk1vwk12q8pjl.cloudfront.net/media/logos/task/middle/flatten-list-disabled.png)
[old] Flatten a List

Nicola likes to categorize all sorts of things. He categorized a series of numbers and as the result of his efforts, a simple sequence of numbers became a deeply-nested list. Sophia and Stephan don't really understand his organization and need to figure out what it all means. They need your help to understand Nikolas crazy list.
There...
CheckiO Extensions allow you to use local files to solve missions. More info in a blog post.
In order to install CheckiO client you'll need installed Python (version at least 3.8)
Install CheckiO Client first:
pip3 install checkio_client
Configure your tool
checkio --domain=js config --key=
Sync solutions into your local folder
checkio sync
(in beta testing) Launch local server so your browser can use it and sync solution between local file end extension on the fly. (doesn't work for safari)
checkio serv -d
Alternatevly, you can install Chrome extension or FF addon
checkio install-plugin
checkio install-plugin --ff
checkio install-plugin --chromium
Read more here about other functionality that the checkio client provides. Feel free to submit an issue in case of any difficulties.