ver_2.py 文件源码

def retrieve_logical(bytes, fielddef, *ignore):
    """
    Returns True if bytes is 't', 'T', 'y', or 'Y'
    None if '?'
    False otherwise
    """
    cls = fielddef[CLASS]
    empty = fielddef[EMPTY]
    bytes = bytes.tostring()
    if bytes in 'tTyY':
        return cls(True)
    elif bytes in 'fFnN':
        return cls(False)
    elif bytes in '? ':
        if empty is NoneType:
            return None
        return empty()
    elif LOGICAL_BAD_IS_NONE:
        return None
    else:
        raise BadDataError('Logical field contained %r' % bytes)
    return typ(bytes)