| """ |
| General functions for HTML manipulation. |
| """ |
| |
| import re as _re |
| from html.entities import html5 as _html5 |
| |
| |
| __all__ = ['escape', 'unescape'] |
| |
| |
| def escape(s, quote=True): |
| """ |
| Replace special characters "&", "<" and ">" to HTML-safe sequences. |
| If the optional flag quote is true (the default), the quotation mark |
| characters, both double quote (") and single quote (') characters are also |
| translated. |
| """ |
| s = s.replace("&", "&") # Must be done first! |
| s = s.replace("<", "<") |
| s = s.replace(">", ">") |
| if quote: |
| s = s.replace('"', """) |
| s = s.replace('\'', "'") |
| return s |
| |
| |
| # see https://html.spec.whatwg.org/multipage/parsing.html#numeric-character-reference-end-state |
| |
| _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 |
| } |
| |
| _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 |
| } |
| |
| |
| 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 _html5: |
| return _html5[s] |
| # find the longest matching name (as defined by the standard) |
| for x in range(len(s)-1, 1, -1): |
| if s[:x] in _html5: |
| return _html5[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};?)') |
| |
| def unescape(s): |
| """ |
| Convert all named and numeric character references (e.g. >, >, |
| &x3e;) in the string s to the corresponding unicode characters. |
| This function uses the rules defined by the HTML 5 standard |
| for both valid and invalid character references, and the list of |
| HTML 5 named character references defined in html.entities.html5. |
| """ |
| if '&' not in s: |
| return s |
| return _charref.sub(_replace_charref, s) |
