TES4Py
This is a parser for .esp/.esm files for The Elder Scrolls IV: Oblivion.
With a little modification it should work for Skyrim, Fallout 3, 4 and New Vegas since the format is very similar.
Uses memory-mapped files with memoryview, and lazy parsing for maximum speed.
Came out of an old project (same name) that used construct3 to parse, but it was too slow when parsing Oblivion.esm
see: https://www.youtube.com/watch?v=w5TLMn5l0g0 for the livestream where I coded this.
This code is very rough.