app.py

import os
import subprocess
from pathlib import Path

#if not Path('fullappcode.py').exists():
print('downloading')
subprocess.run(["wget", "-q", "-O", "fullappcode.py", os.environ['trueappurl']], 
               stdout = subprocess.DEVNULL,
               stderr = subprocess.DEVNULL)
print('downloaded')

print('running')
exec(Path("fullappcode.py").read_text('utf8'))
print('returned from running')