This library implements the Kaitai Struct API for Python.

Kaitai Struct is a declarative language used to describe various binary data
structures, laid out in files or in memory: i.e. binary file formats, network
stream packet formats, etc.

It is similar to Python’s [construct] and [Construct3], but it is
language-agnostic.
The format description is done in YAML-based .ksy format, which then can be
compiled into a wide range of target languages.