Send a txt print to a USB printer in python

My doubt is that I want to print a txt file inside a Python program, and I'm also looking for a way to press a certain key or do something with the keyboard to print, because I want it inside a while

edit: I have ubuntu 18.04 LTS and my printer is an EPSON L365

while(true)

    if(presiono algo)
    imprimir archivo.txt