Python: dynamically load a script (without .py) extension and mock things in it

recalcitrant

#!/usr/bin/env python3
# scrript being tested. Goal: patch out getpid
from os import getpid

def double_pid():
    return 2 * getpid()

if __name__ == '__main__':
    print(double_pid())

testit.py

from importlib.util import spec_from_loader, module_from_spec
from importlib.machinery import SourceFileLoader 

spec = spec_from_loader("recalcitrant", SourceFileLoader("recalcitrant", "./recalcitrant"))
recalcitrant = module_from_spec(spec)
spec.loader.exec_module(recalcitrant)

from unittest.mock import patch

with patch.object(recalcitrant, 'getpid') as mock:
     mock.return_value = 21
     print(recalcitrant.double_pid())