What library provides Offline Human Readable Directions in Text format?

Goal:

1. Offline Directions (No external API's to Clouds or 2 computers connected to each other)
2. Human Readable directions returned in a String format (no api's that return nodes with triple nested brackets, no GUI's that create images) It would look like, "Turn left on Bobsland NW and go 100ft, ...".
3. Can be called from C++ or Python
4. Runs on Raspberry Pi

This is what sketch of what it should look like:

/*
import selfhostedAPIthing;

selfhostedAPIthing myNav = new selfhostedAPIthing;
myNav.setOSMFile("C://Programs/MyApp/OSMExtract/planet.osm");

String destination;
String modeOfTravel= "walk";
String unitSystem= "metric";
sendToMyCustumAppFunction(myNav.getDirections(GPS.getXY(), destination, modeOfTravel, unitSystem));
*/

Thanks in advance

Suggestions: If you maintain a library that does this, consider mentioning the term human readable directions?