import io
from contextlib import redirect_stdout
from compileall import compile_file
from tempfile import TemporaryDirectory
from pathlib import Path

with TemporaryDirectory() as tmpdir:
    invalid_python_file = Path(tmpdir, "script.py")
    invalid_python_file.write_text("invalid python code")

    # works on sys.stdout
    compile_file(invalid_python_file)

    # fails when redirected to io.StringIO
    #   because io.StringIO.encoding is None
    with redirect_stdout(io.StringIO()):
        compile_file(invalid_python_file)