using princore.py

Hello,
I am building systems for analytical chemistry inspired from 3D printing, I use arduino, RAMPS and Marlin to control motors, temperatures, fan etc...
I built my own host software where the GCODE is created and send directly to the printer. The software is written in R, use the shiny library to host a server on a raspberry pi and call a small python script to read and send GCODE files and command to the printer.
My problem is that marlin often miss GCODE lines and do very strange stuffs which do not appear when I send the same GCODE file via pronterface.
I would like to use printcore instead directly from my software to avoid those behaviors but I could use some help as my python is read only.
In attach, the py file I used to communicate with marlin and a typical GCODE file
Dimitri