tako is a command language and shell for GNU/Linux (and Mac OS, and Windows via Cygwin or MSYS2), based on Python (version 3) and GNU Bash, and forked from xonsh.
tako is not "sh"-compatible, but rather is designed to provide an intuitive interface for common shell operations (to reduce time spent looking up how to do things in Bash/sed/awk).
There are three equally valid ways of looking at tako: it is a shell with a sane scripting language, and/or it is Python with extra syntax to make running external commands easier, and/or it is a stripped-down version of xonsh (you can see some of the differences here).
A short list of nice features:
Rich Python ecosystem directly from the shell
Configurable and extensible (via plugins and configuration files)
No more need to search the web every time you want to write a conditional or loop in the shell :)
Details of how to use and/or customize tako are available from the documentation page.
In the meantime, here is a quick (~5 minutes) demo, demonstrating some features of tako: