_header_value_parser.py 文件源码

def get_local_part(value):
    """ local-part = dot-atom / quoted-string / obs-local-part

    """
    local_part = LocalPart()
    leader = None
    if value[0] in CFWS_LEADER:
        leader, value = get_cfws(value)
    if not value:
        raise errors.HeaderParseError(
            "expected local-part but found '{}'".format(value))
    try:
        token, value = get_dot_atom(value)
    except errors.HeaderParseError:
        try:
            token, value = get_word(value)
        except errors.HeaderParseError:
            if value[0] != '\\' and value[0] in PHRASE_ENDS:
                raise
            token = TokenList()
    if leader is not None:
        token[:0] = [leader]
    local_part.append(token)
    if value and (value[0]=='\\' or value[0] not in PHRASE_ENDS):
        obs_local_part, value = get_obs_local_part(str(local_part) + value)
        if obs_local_part.token_type == 'invalid-obs-local-part':
            local_part.defects.append(errors.InvalidHeaderDefect(
                "local-part is not dot-atom, quoted-string, or obs-local-part"))
        else:
            local_part.defects.append(errors.ObsoleteHeaderDefect(
                "local-part is not a dot-atom (contains CFWS)"))
        local_part[0] = obs_local_part
    try:
        local_part.value.encode('ascii')
    except UnicodeEncodeError:
        local_part.defects.append(errors.NonASCIILocalPartDefect(
                "local-part contains non-ASCII characters)"))
    return local_part, value