从sympy/svgmath生成SVG时出错

Question

我尝试使用sympy和svgmath将代数呈现为SVG。我有档案'svgmath.xml文件'在根目录中。不幸的是，我得到了：“ImportError:No module named libxml2”。我不确定最好的解决办法。如有任何帮助/建议，我将不胜感激。我的代码是：

from xml import sax
from xml.sax.saxutils import XMLGenerator

from svgmath.tools.saxtools import XMLGenerator, ContentFilter
from svgmath.mathhandler import MathHandler, MathNS
from svgmath.tools.saxtools import XMLGenerator

from sympy.printing.mathml import mathml
from sympy.abc import x

from sympy.utilities.mathml import c2p

# Open all files
output = open("test.svg", "w") 
config = open("svgmath.xml", "r")    

# Create the converter as a content handler. 
saxoutput = XMLGenerator(output, 'utf-8')
handler = MathHandler(saxoutput, config)

# Parse input file with a namespace-aware SAX parser
parser = sax.make_parser()
parser.setFeature(sax.handler.feature_namespaces, 1)
parser.setContentHandler(handler)
parser.parse(c2p(mathml(3*x), simple=False))

堆栈跟踪现在是：

^{pr2}$

---

我修改的代码：

from xml import sax
from xml.sax.saxutils import XMLGenerator

from svgmath.tools.saxtools import XMLGenerator, ContentFilter
from svgmath.mathhandler import MathHandler, MathNS
from svgmath.tools.saxtools import XMLGenerator

from sympy.printing.mathml import mathml
from sympy.abc import x

from sympy.utilities.mathml import c2p

import libxml2

import StringIO

# Open all files
output = open("test.svg", "w") 
config = open("svgmath.xml", "r")    

# Create the converter as a content handler. 
saxoutput = XMLGenerator(output, 'utf-8')
handler = MathHandler(saxoutput, config)

# Parse input file with a namespace-aware SAX parser
parser = sax.make_parser()
parser.setFeature(sax.handler.feature_namespaces, 1)
parser.setContentHandler(handler)
parser.parse(StringIO.StringIO(mathml(3*x)))

这将无法生成有效的SVG文件，并给出：

[WARNING] line 1, column 0: Root element in MathML document must be 'math'
[WARNING] line 1, column 7: MathML element 'times' is unsupported
[WARNING] line 1, column 15: MathML element 'cn' is unsupported
[WARNING] line 1, column 25: MathML element 'ci' is unsupported
[WARNING] line 1, column 0: MathML element 'apply' is unsupported

Answer 1

安装libxml2库。例如，在ubuntu上，这是python-libxml2包。我也尝试过sympy->；mathml->；svg路由一次，还必须安装该包（iirc是c2p()所需的，它应用XSLT将内容转换为presentation mathml）。在