TiffTags.py 文件源码

def lookup(tag):
    """
    :param tag: Integer tag number
    :returns: Taginfo namedtuple, From the TAGS_V2 info if possible,
        otherwise just populating the value and name from TAGS.
        If the tag is not recognized, "unknown" is returned for the name

    """

    return TAGS_V2.get(tag, TagInfo(tag, TAGS.get(tag, 'unknown')))


##
# Map tag numbers to tag info.
#
#  id: (Name, Type, Length, enum_values)
#
# The length here differs from the length in the tiff spec.  For
# numbers, the tiff spec is for the number of fields returned. We
# agree here.  For string-like types, the tiff spec uses the length of
# field in bytes.  In Pillow, we are using the number of expected
# fields, in general 1 for string-like types.