def valid_xml_char_ordinal(c):
codepoint = ord(c)
# conditions ordered by presumed frequency
return (
0x20 <= codepoint <= 0xD7FF or
codepoint in (0x9, 0xA, 0xD) or
0xE000 <= codepoint <= 0xFFFD or
0x10000 <= codepoint <= 0x10FFFF
)