story-json | Story JSON document format | JSON Processing library

I have a series of gigantic (40-80mb) exported Google Location History JSON files, with which I've been tasked to analyze select activity data. Unfortunately Google has no parameter or option at their download site to choose anything except "one giant JSON containing forever". (The KML option is twice as big.)

Obvious choices like JSON-Converter (laexcel-test incarnation of VBA-JSON); parsing line-by line with VBA; even Notepad++. They all crash and burn. I'm thinking RegEx might be the answer.

1. This Python script can extract the timestamp and location from a 40mb file in two seconds (with RegEx?). How is Python doing it so fast? (Would it be as fast in VBA?)

2. I'd be able to extract everything I need, piece by piece, if only I had a magic chunk of RegEx, perhaps with this logic:

   • Delete everything except:
     When timestampMs and WALKING appear between the *same set of [square brackets] :

     • I need the 13-digit number that follows timestampMS, and,
     • the one- to three- digit number that follows WALKING.

If it's simpler to include a little more data, like "all the timestamps", or "all activities", I could easily sift through it later. The goal is to make the file small enough that I can manipulate it without the need to rent a supercomputer, lol.

^{I tried adapting existing RegEx's but I have a serious issue with both RegEx and musical instruments: doesn't how hard I try, I just can't wrap my head around it. So, this is indeed a "please write code for me" question, but it's just one expression, and I'll pay it forward by writing code for others today! Thanks...} ☺ .