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python - 通过本地 MathML DTD 验证 MathML xml 字符串

问题描述

我正在尝试以这种方式使用 lxml 验证 MathML XML 字符串：

import lxml.etree
mathml = """
<!DOCTYPE math PUBLIC "-//W3C//DTD MathML 3.0//EN" "http://www.w3.org/Math/DTD/mathml3/mathml3.dtd">
<math xmlns="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">
  <mi>a</mi>
  <mo>+</mo>
  <mi>b</mi>
</math>
"""
lxml_parser = lxml.etree.XMLParser(
    dtd_validation=True,
    no_network=False,
    load_dtd=True,
    ns_clean=True,
    remove_blank_text=True,
)
validated = lxml.etree.fromstring(xml, lxml_parser)

通过这种方式，它检查 mathml 字符串中指定的 DTD 并通过网络验证字符串。

问题

当没有可用的 nwtwork 时，如何根据本地 DTD 验证 mathml 字符串？

我试过的

我从 https://www.w3.org/Math/DTD/mathml3/mathml3.dtd 下载了 MathML DTD 3，从https://www.w3.org/Math/DTD/mathml1/下载了MathML DTD 1 mathml.dtd并将它们保存在当前工作目录中，我已将 DOCTYPE 声明更改为指向本地 DTD，例如<!DOCTYPE math SYSTEM "path/to/mathml_dtd.dtd">，我终于创建了 lxml.etree.XMLParser no_network=True，但是当我运行以下代码时

import lxml.etree
mathml = """
<!DOCTYPE math SYSTEM "path/to/dtd/mathml3.dtd">
<math xmlns="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">
  <mrow>
    <mo>&lfloor;</mo>
    <mrow>
      <mi>a</mi>
    </mrow>
    <mo>&rfloor;</mo>
  </mrow>
</math>
"""
lxml_parser = lxml.etree.XMLParser(
    dtd_validation=True,
    no_network=True,
    load_dtd=True,
    ns_clean=True,
    remove_blank_text=True,
)
validated = lxml.etree.fromstring(xml, lxml_parser)

我有这个错误：

File "/projects/py_asciimath/py_asciimath/parser/parser.py", line 117, in __dtd_validation
    return lxml.etree.fromstring(xml, lxml_parser)
  File "src/lxml/etree.pyx", line 3235, in lxml.etree.fromstring
  File "src/lxml/parser.pxi", line 1876, in lxml.etree._parseMemoryDocument
  File "src/lxml/parser.pxi", line 1757, in lxml.etree._parseDoc
  File "src/lxml/parser.pxi", line 1068, in lxml.etree._BaseParser._parseUnicodeDoc
  File "src/lxml/parser.pxi", line 601, in lxml.etree._ParserContext._handleParseResultDoc
  File "src/lxml/parser.pxi", line 711, in lxml.etree._handleParseResult
  File "src/lxml/parser.pxi", line 640, in lxml.etree._raiseParseError
  File "/projects/py_asciimath/py_asciimath/translation/dtd/mathml3.dtd", line 36
lxml.etree.XMLSyntaxError: conditional section INCLUDE or IGNORE keyword expected, line 36, column 17

使用 MathML DTD 1 的本地副本，我得到了这个：

File "/projects/py_asciimath/py_asciimath/parser/parser.py", line 117, in __dtd_validation
    return lxml.etree.fromstring(xml, lxml_parser)
  File "src/lxml/etree.pyx", line 3235, in lxml.etree.fromstring
  File "src/lxml/parser.pxi", line 1876, in lxml.etree._parseMemoryDocument
  File "src/lxml/parser.pxi", line 1757, in lxml.etree._parseDoc
  File "src/lxml/parser.pxi", line 1068, in lxml.etree._BaseParser._parseUnicodeDoc
  File "src/lxml/parser.pxi", line 601, in lxml.etree._ParserContext._handleParseResultDoc
  File "src/lxml/parser.pxi", line 711, in lxml.etree._handleParseResult
  File "src/lxml/parser.pxi", line 640, in lxml.etree._raiseParseError
  File "<string>", line 1
lxml.etree.XMLSyntaxError: Entity 'lfloor' not defined, line 1, column 135

标签： pythonxmllxmlmathmldtd-parsing

解决方案

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