How to close Music & TV windows app with python

Question

I opened mp4 video with my python script. Now I want to close this video but i am not sure how. I use Movies & TV app for Windows10 to play video.

For chrome i used this lines of code and work perfectly

if checkIfProcessRunning('chrome'):
  os.system("taskkill /im chrome.exe /f")

for playing video I use

from os import startfile

startfile("1.mp4")

I try to find path for app i use but no luck