{"record":{"id":"06fae2e99da4e606","repo":"python/cpython","slug":"unexpected-r-char-in-declaration","errorCode":null,"errorMessage":"unexpected %r char in declaration","messagePattern":"unexpected %r char in declaration","errorType":"exception","errorClass":"AssertionError","httpStatus":null,"severity":"error","filePath":"Lib/_markupbase.py","lineNumber":134,"sourceCode":" j = m.end()\n elif c in \"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ\":\n name, j = self._scan_name(j, i)\n elif c in self._decl_otherchars:\n j = j + 1\n elif c == \"[\":\n # this could be handled in a separate doctype parser\n if decltype == \"doctype\":\n j = self._parse_doctype_subset(j + 1, i)\n elif decltype in {\"attlist\", \"linktype\", \"link\", \"element\"}:\n # must tolerate []'d groups in a content model in an element declaration\n # also in data attribute specifications of attlist declaration\n # also link type declaration subsets in linktype declarations\n # also link attribute specification lists in link declarations\n raise AssertionError(\"unsupported '[' char in %s declaration\" % decltype)\n else:\n raise AssertionError(\"unexpected '[' char in declaration\")\n else:\n raise AssertionError(\"unexpected %r char in declaration\" % rawdata[j])\n if j < 0:\n return j\n return -1 # incomplete\n\n # Internal -- parse a marked section\n # Override this to handle MS-word extension syntax content\n def parse_marked_section(self, i, report=1):\n rawdata= self.rawdata\n assert rawdata[i:i+3] == ' ending\n match= _markedsectionclose.search(rawdata, i+3)\n elif sectName in {\"if\", \"else\", \"endif\"}:\n # look for MS Office ]> ending\n match= _msmarkedsectionclose.search(rawdata, i+3)","sourceCodeStart":116,"sourceCodeEnd":152,"githubUrl":"https://github.com/python/cpython/blob/bc6749cc3b5ae4a5e88a6cc2d5b3bebbe354eae6/Lib/_markupbase.py#L116-L152","documentation":"AssertionError raised by _markupbase.ParserBase._scan_decl when a declaration contains a character the scanner has no rule for — not a name char, not one of _decl_otherchars, not '['. It is the catch-all for malformed bodies, echoing the offending character.","triggerScenarios":"HTMLParser.feed() with a declaration containing stray punctuation/control characters, e.g. or ; unterminated or truncated declarations at buffer end can also leave the cursor on an unexpected character.","commonSituations":"Parsing minified/mangled HTML, template fragments with leftover '' before continuing.","For untrusted HTML, run a repair pass (html5lib, bleach.cleaner) before stdlib parsing."],"exampleFix":"# before\nHTMLParser().feed(\"\") # AssertionError: unexpected '^' char in declaration\n\n# after\nraw = re.sub(r']*>', lambda m: m.group(0) if m.group(1).lower()=='doctype' else '', raw)\nHTMLParser().feed(raw)","handlingStrategy":"try-catch","validationCode":"import re\n_BAD_DECL_CHAR = re.compile(r']*[^\\w\\s\\[\\]\\|()\\'\\\",#%-]>')\n\ndef decl_chars_ok(raw: str) -> bool:\n return not _BAD_DECL_CHAR.search(raw)","typeGuard":null,"tryCatchPattern":"try:\n parser.feed(chunk)\nexcept AssertionError as e:\n if 'char in declaration' in str(e):\n chunk = re.sub(r']*>', '', chunk) # drop the offending declaration\n parser.reset(); parser.feed(chunk)\n else:\n raise","preventionTips":["Always call parser.close() after the last feed() so truncated declarations resolve or fail cleanly.","Pre-filter stray '