import re
from html.entities import entitydefs
# Helpers for xhtml-im
SAFE_ENTITIES = {
e: entitydefs[e] for e in entitydefs if e not in ("amp", "quot", "apos", "gt", "lt")
}
_invalid_codepoints = {
# 0x0001 to 0x0008
0x1,
0x2,
0x3,
0x4,
0x5,
0x6,
0x7,
0x8,
# 0x000E to 0x001F
0xE,
0xF,
0x10,
0x11,
0x12,
0x13,
0x14,
0x15,
0x16,
0x17,
0x18,
0x19,
0x1A,
0x1B,
0x1C,
0x1D,
0x1E,
0x1F,
# 0x007F to 0x009F
0x7F,
0x80,
0x81,
0x82,
0x83,
0x84,
0x85,
0x86,
0x87,
0x88,
0x89,
0x8A,
0x8B,
0x8C,
0x8D,
0x8E,
0x8F,
0x90,
0x91,
0x92,
0x93,
0x94,
0x95,
0x96,
0x97,
0x98,
0x99,
0x9A,
0x9B,
0x9C,
0x9D,
0x9E,
0x9F,
# 0xFDD0 to 0xFDEF
0xFDD0,
0xFDD1,
0xFDD2,
0xFDD3,
0xFDD4,
0xFDD5,
0xFDD6,
0xFDD7,
0xFDD8,
0xFDD9,
0xFDDA,
0xFDDB,
0xFDDC,
0xFDDD,
0xFDDE,
0xFDDF,
0xFDE0,
0xFDE1,
0xFDE2,
0xFDE3,
0xFDE4,
0xFDE5,
0xFDE6,
0xFDE7,
0xFDE8,
0xFDE9,
0xFDEA,
0xFDEB,
0xFDEC,
0xFDED,
0xFDEE,
0xFDEF,
# others
0xB,
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,
}
_invalid_charrefs = {
0x00: "\ufffd", # REPLACEMENT CHARACTER
0x0D: "\r", # CARRIAGE RETURN
0x80: "\u20ac", # EURO SIGN
0x81: "\x81", # <control>
0x82: "\u201a", # SINGLE LOW-9 QUOTATION MARK
0x83: "\u0192", # LATIN SMALL LETTER F WITH HOOK
0x84: "\u201e", # DOUBLE LOW-9 QUOTATION MARK
0x85: "\u2026", # HORIZONTAL ELLIPSIS
0x86: "\u2020", # DAGGER
0x87: "\u2021", # DOUBLE DAGGER
0x88: "\u02c6", # MODIFIER LETTER CIRCUMFLEX ACCENT
0x89: "\u2030", # PER MILLE SIGN
0x8A: "\u0160", # LATIN CAPITAL LETTER S WITH CARON
0x8B: "\u2039", # SINGLE LEFT-POINTING ANGLE QUOTATION MARK
0x8C: "\u0152", # LATIN CAPITAL LIGATURE OE
0x8D: "\x8d", # <control>
0x8E: "\u017d", # LATIN CAPITAL LETTER Z WITH CARON
0x8F: "\x8f", # <control>
0x90: "\x90", # <control>
0x91: "\u2018", # LEFT SINGLE QUOTATION MARK
0x92: "\u2019", # RIGHT SINGLE QUOTATION MARK
0x93: "\u201c", # LEFT DOUBLE QUOTATION MARK
0x94: "\u201d", # RIGHT DOUBLE QUOTATION MARK
0x95: "\u2022", # BULLET
0x96: "\u2013", # EN DASH
0x97: "\u2014", # EM DASH
0x98: "\u02dc", # SMALL TILDE
0x99: "\u2122", # TRADE MARK SIGN
0x9A: "\u0161", # LATIN SMALL LETTER S WITH CARON
0x9B: "\u203a", # SINGLE RIGHT-POINTING ANGLE QUOTATION MARK
0x9C: "\u0153", # LATIN SMALL LIGATURE OE
0x9D: "\x9d", # <control>
0x9E: "\u017e", # LATIN SMALL LETTER Z WITH CARON
0x9F: "\u0178", # LATIN CAPITAL LETTER Y WITH DIAERESIS
}
def _replace_charref(s):
s = s.group(1)
if s[0] == "#":
# numeric charref
if s[1] in "xX":
num = int(s[2:].rstrip(";"), 16)
else:
num = int(s[1:].rstrip(";"))
if num in _invalid_charrefs:
return _invalid_charrefs[num]
if 0xD800 <= num <= 0xDFFF or num > 0x10FFFF:
return "\uFFFD"
if num in _invalid_codepoints:
return ""
return chr(num)
else:
# named charref
if s in SAFE_ENTITIES:
return SAFE_ENTITIES[s]
# find the longest matching name (as defined by the standard)
for x in range(len(s) - 1, 1, -1):
if s[:x] in SAFE_ENTITIES:
return SAFE_ENTITIES[s[:x]] + s[x:]
else:
return "&" + s
_charref = re.compile(
r"&(#[0-9]+;?" r"|#[xX][0-9a-fA-F]+;?" r"|[^\t\n\f <&#;]{1,32};?)"
)
[docs]
def unescape(s):
if "&" not in s:
return s
return _charref.sub(_replace_charref, s)
