import subprocess

cmd = [
    r"C:\Users\******\Desktop\mayo\mayo\mayo.exe",
    r"C:\Users\******\Desktop\*****.STEP",
    "-s", r"C:\Users\******\Desktop\mayo\mayo\option.ini",
    "-e", r"C:\Users\******\Desktop\*****.glb"
]

process = subprocess.Popen(cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
stdout, stderr = process.communicate()

print("STDOUT:", stdout.decode())
print("STDERR:", stderr.decode())