def get_version(file):
    """
    Detect the version of Python used for a submission.
    """
    with open(file, 'rb') as pyz:
        if pyz.read(2) == b'#!':
            version = pyz.readline().rsplit(b'python', 2)[1].strip()
            if version in (b'3.8',):
                return version.decode()
        return '3.8'