[Python-checkins] cpython: #2927: Added the unescape() function to the html module.
ezio.melotti
python-checkins at python.org
Tue Nov 19 19:29:16 CET 2013
http://hg.python.org/cpython/rev/7b9235852b3b
changeset: 87275:7b9235852b3b
parent: 87273:ee2c80eeca2a
user: Ezio Melotti <ezio.melotti at gmail.com>
date: Tue Nov 19 20:28:45 2013 +0200
summary:
#2927: Added the unescape() function to the html module.
files:
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
--- a/Doc/library/html.entities.rst
+++ b/Doc/library/html.entities.rst
@@ -20,6 +20,7 @@
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
--- a/Doc/library/html.rst
+++ b/Doc/library/html.rst
@@ -20,6 +20,17 @@
.. 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 <html.entities.html5>`.
+
+ .. versionadded:: 3.4
+
--------------
Submodules in the ``html`` package are:
diff --git a/Lib/html/__init__.py b/Lib/html/__init__.py
--- 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 @@
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', # <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)
diff --git a/Lib/html/parser.py b/Lib/html/parser.py
--- 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 @@
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 @@
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
--- a/Lib/test/test_html.py
+++ b/Lib/test/test_html.py
@@ -16,9 +16,89 @@
html.escape('\'<script>"&foo;"</script>\'', 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
--- a/Lib/test/test_htmlparser.py
+++ b/Lib/test/test_htmlparser.py
@@ -569,18 +569,6 @@
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 = ('<! not really a comment >'
'<! not a comment either -->'
diff --git a/Misc/NEWS b/Misc/NEWS
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -59,6 +59,8 @@
- 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.
--
Repository URL: http://hg.python.org/cpython
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