""" 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("&", "&amp;") # Must be done first! s = s.replace("<", "&lt;") s = s.replace(">", "&gt;") if quote: s = s.replace('"', "&quot;") s = s.replace('\'', "&#x27;") return s # see http://www.w3.org/TR/html5/syntax.html#tokenizing-character-references _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. &gt;, &#62;, &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)