def _convert_to_3(path):  # pragma: no cover
    """Convert python 2 file to python 3."""
    try:
        log.warn('##### Trying to convert %s to Python 3. #####', path)
        subprocess.call(['2to3', '-w', path])
    except subprocess.SubprocessError:
        log.exception('Check if 2to3 is installed. https://docs.python.org/2/library/2to3.html')
        exit(1)
Convert python 2 file to python 3.