convert cartesian cordinate of a points in an area to gps coordinate using python (Its probably a snipset of code, Pls The price should not be more than 10 eur.)

The task is that assume you have Cartesian like coordinate values like (X,Y,Z) wrt an origin chosen in a real world(assume an origin (0,0,0) at your home entrance door base, now you can calculate (x,y,z) co-ordiantes for your bedroom entrance(x1,y1,z1), kitchen entrance(x2,y2,z2), toilet entrance (x3,y3,z3) w.r.t the origin at main entrance (0,0,0))
now i need gps coordinates for all the above Cartesian coordinates from (0,0,0) to (x3,y3,z3). PLs I do not have more than 10 eur