Deserialize fp (a file-like object) to a Python object.

def load(fp, model=None, parser=None):
    """Deserialize fp (a file-like object) to a Python object."""
    if not model:
        model = 'simple'
    if not parser:
        parser = 'quick'

    if model not in ['simple']:
        raise ValueError
    if parser not in ['quick']:
        raise ValueError

    if model == 'simple' and parser == 'quick':
        return ARPAParserQuick(ARPAModelSimple).parse(fp)
    else:
        raise ValueError