import subprocess

print("Starting subprocess...")
p = subprocess.run(
    [
        r"C:\pathto\python.exe",
        "-c",
        'print("Hi from subprocess"); import time; time.sleep(3); import sys; sys.exit()',
    ],
    text=True,
    stdout=subprocess.PIPE,
)
print(p.stdout)

print("Starting subprocess...")
p = subprocess.call("taskkill /F /IM notepad.exe")