Escape invalid XML characters in Python 3

escape_xml.py

#!/usr/bin/env python3

import sys
import re

# https://trac-hacks.org/ticket/11050#comment:13
_illegal_unichrs = ((0x00, 0x08), (0x0B, 0x1F), (0x7F, 0x84), (0x86, 0x9F),
                    (0xD800, 0xDFFF), (0xFDD0, 0xFDDF), (0xFFFE, 0xFFFF),
                    (0x1FFFE, 0x1FFFF), (0x2FFFE, 0x2FFFF),
                    (0x3FFFE, 0x3FFFF), (0x4FFFE, 0x4FFFF),
                    (0x5FFFE, 0x5FFFF), (0x6FFFE, 0x6FFFF),
                    (0x7FFFE, 0x7FFFF), (0x8FFFE, 0x8FFFF),
                    (0x9FFFE, 0x9FFFF), (0xAFFFE, 0xAFFFF),
                    (0xBFFFE, 0xBFFFF), (0xCFFFE, 0xCFFFF),
                    (0xDFFFE, 0xDFFFF), (0xEFFFE, 0xEFFFF),
                    (0xFFFFE, 0xFFFFF), (0x10FFFE, 0x10FFFF))
_illegal_ranges = tuple("%s-%s" % (chr(low), chr(high))
                        for (low, high) in _illegal_unichrs
                        if low < sys.maxunicode)
_illegal_xml_chars_re = re.compile('[%s]' % ''.join(_illegal_ranges))


def _escape_match(match):
    return '&#%i;' % ord(match.group(0))


def escape_xml_invalid_chars(xml_text):
    return _illegal_xml_chars_re.sub(_escape_match, xml_text)