From 4a9ee26750aa8cb37b5072b2bb4dd328819febb4 Mon Sep 17 00:00:00 2001 From: Ezio Melotti Date: Tue, 19 Nov 2013 20:28:45 +0200 Subject: [PATCH] #2927: Added the unescape() function to the html module. --- Doc/library/html.entities.rst | 1 + Doc/library/html.rst | 11 ++++ Lib/html/__init__.py | 114 +++++++++++++++++++++++++++++++++- Lib/html/parser.py | 38 ++---------- Lib/test/test_html.py | 86 ++++++++++++++++++++++++- Lib/test/test_htmlparser.py | 12 ---- Misc/NEWS | 2 + 7 files changed, 215 insertions(+), 49 deletions(-) diff --git a/Doc/library/html.entities.rst b/Doc/library/html.entities.rst index 65ce817b3e1..ba8324ca711 100644 --- a/Doc/library/html.entities.rst +++ b/Doc/library/html.entities.rst @@ -20,6 +20,7 @@ This module defines four dictionaries, :data:`html5`, Note that the trailing semicolon is included in the name (e.g. ``'gt;'``), however some of the names are accepted by the standard even without the semicolon: in this case the name is present with and without the ``';'``. + See also :func:`html.unescape`. .. versionadded:: 3.3 diff --git a/Doc/library/html.rst b/Doc/library/html.rst index 1107ca9b8a6..d0706bcbc07 100644 --- a/Doc/library/html.rst +++ b/Doc/library/html.rst @@ -20,6 +20,17 @@ This module defines utilities to manipulate HTML. .. versionadded:: 3.2 + +.. function:: 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 :data:`list of + HTML 5 named character references `. + + .. versionadded:: 3.4 + -------------- Submodules in the ``html`` package are: diff --git a/Lib/html/__init__.py b/Lib/html/__init__.py index 2ad167f16af..da0a0a3ce70 100644 --- a/Lib/html/__init__.py +++ b/Lib/html/__init__.py @@ -2,7 +2,12 @@ General functions for HTML manipulation. """ -# NB: this is a candidate for a bytes/string polymorphic interface +import re as _re +from html.entities import html5 as _html5 + + +__all__ = ['escape', 'unescape'] + def escape(s, quote=True): """ @@ -18,3 +23,110 @@ def escape(s, quote=True): s = s.replace('"', """) s = s.replace('\'', "'") 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', # + 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', # + 0x8e: '\u017d', # LATIN CAPITAL LETTER Z WITH CARON + 0x8f: '\x8f', # + 0x90: '\x90', # + 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', # + 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) diff --git a/Lib/html/parser.py b/Lib/html/parser.py index 22498db4a0d..e793c37cd80 100644 --- a/Lib/html/parser.py +++ b/Lib/html/parser.py @@ -8,9 +8,12 @@ # and CDATA (character data -- only end tags are special). -import _markupbase import re import warnings +import _markupbase + +from html import unescape + __all__ = ['HTMLParser'] @@ -357,7 +360,7 @@ class HTMLParser(_markupbase.ParserBase): attrvalue[:1] == '"' == attrvalue[-1:]: attrvalue = attrvalue[1:-1] if attrvalue: - attrvalue = self.unescape(attrvalue) + attrvalue = unescape(attrvalue) attrs.append((attrname.lower(), attrvalue)) k = m.end() @@ -510,34 +513,3 @@ class HTMLParser(_markupbase.ParserBase): def unknown_decl(self, data): if self.strict: self.error("unknown declaration: %r" % (data,)) - - # Internal -- helper to remove special character quoting - def unescape(self, s): - if '&' not in s: - return s - def replaceEntities(s): - s = s.groups()[0] - try: - if s[0] == "#": - s = s[1:] - if s[0] in ['x','X']: - c = int(s[1:].rstrip(';'), 16) - else: - c = int(s.rstrip(';')) - return chr(c) - except ValueError: - return '&#' + s - else: - from html.entities import html5 - if s in html5: - return html5[s] - elif s.endswith(';'): - return '&' + s - for x in range(2, len(s)): - if s[:x] in html5: - return html5[s[:x]] + s[x:] - else: - return '&' + s - - return re.sub(r"&(#?[xX]?(?:[0-9a-fA-F]+;|\w{1,32};?))", - replaceEntities, s, flags=re.ASCII) diff --git a/Lib/test/test_html.py b/Lib/test/test_html.py index 30dac58e6d0..5e9f382a2d1 100644 --- a/Lib/test/test_html.py +++ b/Lib/test/test_html.py @@ -16,9 +16,89 @@ class HtmlTests(unittest.TestCase): html.escape('\'\'', False), '\'<script>"&foo;"</script>\'') + def test_unescape(self): + numeric_formats = ['&#%d', '&#%d;', '&#x%x', '&#x%x;'] + errmsg = 'unescape(%r) should have returned %r' + def check(text, expected): + self.assertEqual(html.unescape(text), expected, + msg=errmsg % (text, expected)) + def check_num(num, expected): + for format in numeric_formats: + text = format % num + self.assertEqual(html.unescape(text), expected, + msg=errmsg % (text, expected)) + # check text with no character references + check('no character references', 'no character references') + # check & followed by invalid chars + check('&\n&\t& &&', '&\n&\t& &&') + # check & followed by numbers and letters + check('&0 &9 &a &0; &9; &a;', '&0 &9 &a &0; &9; &a;') + # check incomplete entities at the end of the string + for x in ['&', '&#', '&#x', '&#X', '&#y', '&#xy', '&#Xy']: + check(x, x) + check(x+';', x+';') + # check several combinations of numeric character references, + # possibly followed by different characters + formats = ['&#%d', '&#%07d', '&#%d;', '&#%07d;', + '&#x%x', '&#x%06x', '&#x%x;', '&#x%06x;', + '&#x%X', '&#x%06X', '&#X%x;', '&#X%06x;'] + for num, char in zip([65, 97, 34, 38, 0x2603, 0x101234], + ['A', 'a', '"', '&', '\u2603', '\U00101234']): + for s in formats: + check(s % num, char) + for end in [' ', 'X']: + check((s+end) % num, char+end) + # check invalid codepoints + for cp in [0xD800, 0xDB00, 0xDC00, 0xDFFF, 0x110000]: + check_num(cp, '\uFFFD') + # check more invalid codepoints + for cp in [0x1, 0xb, 0xe, 0x7f, 0xfffe, 0xffff, 0x10fffe, 0x10ffff]: + check_num(cp, '') + # check invalid numbers + for num, ch in zip([0x0d, 0x80, 0x95, 0x9d], '\r\u20ac\u2022\x9d'): + check_num(num, ch) + # check small numbers + check_num(0, '\uFFFD') + check_num(9, '\t') + # check a big number + check_num(1000000000000000000, '\uFFFD') + # check that multiple trailing semicolons are handled correctly + for e in ['";', '";', '";', '";']: + check(e, '";') + # check that semicolons in the middle don't create problems + for e in ['"quot;', '"quot;', '"quot;', '"quot;']: + check(e, '"quot;') + # check triple adjacent charrefs + for e in ['"', '"', '"', '"']: + check(e*3, '"""') + check((e+';')*3, '"""') + # check that the case is respected + for e in ['&', '&', '&', '&']: + check(e, '&') + for e in ['&Amp', '&Amp;']: + check(e, e) + # check that non-existent named entities are returned unchanged + check('&svadilfari;', '&svadilfari;') + # the following examples are in the html5 specs + check('¬it', '¬it') + check('¬it;', '¬it;') + check('¬in', '¬in') + check('∉', '∉') + # a similar example with a long name + check('¬ReallyAnExistingNamedCharacterReference;', + '¬ReallyAnExistingNamedCharacterReference;') + # longest valid name + check('∳', '∳') + # check a charref that maps to two unicode chars + check('∾̳', '\u223E\u0333') + check('&acE', '&acE') + # see #12888 + check('{ ' * 1050, '{ ' * 1050) + # see #15156 + check('ÉricÉric&alphacentauriαcentauri', + 'ÉricÉric&alphacentauriαcentauri') + check('&co;', '&co;') -def test_main(): - run_unittest(HtmlTests) if __name__ == '__main__': - test_main() + unittest.main() diff --git a/Lib/test/test_htmlparser.py b/Lib/test/test_htmlparser.py index 8863316a0f3..a943d3a4530 100644 --- a/Lib/test/test_htmlparser.py +++ b/Lib/test/test_htmlparser.py @@ -569,18 +569,6 @@ class HTMLParserTolerantTestCase(HTMLParserStrictTestCase): for html, expected in data: self._run_check(html, expected) - def test_unescape_function(self): - p = self.get_collector() - self.assertEqual(p.unescape('&#bad;'),'&#bad;') - self.assertEqual(p.unescape('&'),'&') - # see #12888 - self.assertEqual(p.unescape('{ ' * 1050), '{ ' * 1050) - # see #15156 - self.assertEqual(p.unescape('ÉricÉric' - '&alphacentauriαcentauri'), - 'ÉricÉric&alphacentauriαcentauri') - self.assertEqual(p.unescape('&co;'), '&co;') - def test_broken_comments(self): html = ('' '' diff --git a/Misc/NEWS b/Misc/NEWS index 1ceffb1b346..3da2567562b 100644 --- a/Misc/NEWS +++ b/Misc/NEWS @@ -59,6 +59,8 @@ Library - Issue #19449: in csv's writerow, handle non-string keys when generating the error message that certain keys are not in the 'fieldnames' list. +- Issue #2927: Added the unescape() function to the html module. + - Issue #8402: Added the escape() function to the glob module. - Issue #17618: Add Base85 and Ascii85 encoding/decoding to the base64 module.