使用xml.dom.minidom时,在xml中转义'<'和'>'

Question

我在使用xml.dom.minidom在xml文件中转义"<"和">"时遇到困难.我试图获取unicode十六进制值并使用它而不是
http://slayeroffice.com/tools/unicode_lookup/

试图使用标准"<"和">",但仍然没有成功.

from xml.dom.minidom import Document
doc = Document()
e = doc.createElement("abc")
s1 = '<hello>bhaskar</hello>'
text = doc.createTextNode(s1)
e.appendChild(text)

e.toxml()
'<abc>&lt;hello&gt;bhaskar&lt;/hello&gt;</abc>'

与writexml()相同的结果还尝试通过在toxml()writexml()调用中指定编码'UTF-8','utf-8','utf'但结果相同.

from xml.dom.minidom import Document
doc = Document()
e = doc.createElement("abc")
s1 = u'<hello>bhaskar</hello>'
text = doc.createTextNode(s1)
e.appendChild(text)

e.toxml()
u'<abc>&amp;lt;hello&amp;gt;bhaskar&amp;lt;/hello&amp;gt;</abc>'

试过其他方法,但结果相同.只有这样才能解决问题

import xml.dom.minidom as md
# XXX Hack to handle '<' and '>'
def wd(writer, data):
    data = data.replace("&lt;", "<").replace("&gt;", ">")
    writer.write(data)

md._write_data = wd

编辑 - 这是代码.

    import xml.dom.minidom as md
    doc = md.Document()

    entity_descr = doc.createElement("EntityDescriptor")
    doc.appendChild(entity_descr)
    entity_descr.setAttribute('xmlns', 'urn:oasis:names:tc:SAML:2.0:metadata')
    entity_descr.setAttribute('xmlns:saml', 'urn:oasis:names:tc:SAML:2.0:assertion')
    entity_descr.setAttribute('xmlns:ds', 'http://www.w3.org/2000/09/xmldsig#')
    # Get the entity_id from saml20_idp_settings
    entity_descr.setAttribute('entityID', self.group['entity_id'])

    idpssodescr = doc.createElement('IDPSSODescriptor')
    idpssodescr.setAttribute('WantAuthnRequestsSigned', 'true')
    idpssodescr.setAttribute('protocolSupportEnumeration', 
    'urn:oasis:names:tc:SAML:2.0:protocol')
    entity_descr.appendChild(idpssodescr)

    keydescr = doc.createElement('KeyDescriptor')
    keydescr.setAttribute('use', 'signing')
    idpssodescr.appendChild(keydescr)
    keyinfo = doc.createElement('ds:KeyInfo')
    keyinfo.setAttribute('xmlns:ds', 'http://www.w3.org/2000/09/xmldsig#')
    keydescr.appendChild(keyinfo)
    x509data = doc.createElement('ds:X509Data')
    keyinfo.appendChild(x509data)


    # check this part 

    s = "this is a cert  blah blah"
    x509cert = doc.createElement('ds:X509Certificate')
    cert = doc.createTextNode(s)
    x509cert.appendChild(cert)
    x509data.appendChild(x509cert)

    sso = doc.createElement('SingleSignOnService')
    sso.setAttribute('Binding', 'urn:oasis:names:tc:SAML:2.0:bindings:HTTP-Redirect')

    sso.setAttribute('Location', 'http://googleapps/singleSignOn')
    idpssodescr.appendChild(sso)

    # Write the metadata file.
    fobj = open('metadata.xml', 'w')
    doc.writexml(fobj, "   ", "", "\n", "UTF-8")
    fobj.close()

这产生了

   <?xml version="1.0" encoding="UTF-8"?>
   <EntityDescriptor entityID="skar" xmlns="urn:oasis:names:tc:SAML:2.0:metadata"    
   xmlns:ds="http://www.w3.org/2000/09/xmldsig#" 
   xmlns:saml="urn:oasis:names:tc:SAML:2.0:assertion">
   <IDPSSODescriptor WantAuthnRequestsSigned="true"   
   protocolSupportEnumeration="urn:oasis:names:tc:SAML:2.0:protocol">
   <KeyDescriptor use="signing">
   <ds:KeyInfo xmlns:ds="http://www.w3.org/2000/09/xmldsig#">
   <ds:X509Data>
   <ds:X509Certificate>
    this is a cert  blah blah
   </ds:X509Certificate>
   </ds:X509Data>
   </ds:KeyInfo>
   </KeyDescriptor>
   <SingleSignOnService Binding="urn:oasis:names:tc:SAML:2.0:bindings:HTTP-Redirect" 
   Location="http:///singleSignOn"/>
   </IDPSSODescriptor>
   </EntityDescriptor>

请注意"这是一个证书"单独出现我已经打破了我的头,但结果相同.

Answer 1

这不是一个错误,它是一个功能.要插入实际的XML,请插入DOM对象.XML标记内的文本需要实体转义才能成为有效的XML.

from xml.dom.minidom import Document
doc = Document()
e = doc.createElement("abc")
eh = doc.createElement("hello")
s1 = 'bhaskar'
text = doc.createTextNode(s1)

eh.appendChild(text)
e.appendChild(eh)

e.toxml()

编辑:我不知道Python的API是什么样的,但它看起来非常类似于C#,所以你可能会做一些类似于e.innerXml = s1做你想做的事情......但这可能很糟糕.更好的做法是解析它和appendChild它.

编辑2:我刚刚在本地通过Python运行,并且肯定会出现问题,而不是库中.请确保您的字符串没有任何换行符或空格在它的开始.作为参考,我使用的测试代码是:

Python 2.6.2 (release26-maint, Apr 19 2009, 01:56:41) 
[GCC 4.3.3] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> from xml.dom.minidom import Document
>>> cert = "---- START CERTIFICATE ----\n   Hello world\n---- END CERTIFICATE ---"
>>> doc = Document()
>>> e = doc.createElement("cert")
>>> certEl = doc.createTextNode(cert)
>>> e.appendChild(certEl)
<DOM Text node "'---- START'...">
>>> print e.toxml()
<cert>---- START CERTIFICATE ----
   Hello world
---- END CERTIFICATE ---</cert>
>>> 

编辑3:最后的编辑.问题出在你的writexml电话里.只需使用以下修复:

doc.writexml(fobj)
# or
doc.writexml(fobj, "", "  ", "")

不幸的是,似乎你将无法使用该newline参数来获得漂亮的打印......似乎Python库(或至少minidom)编写得相当差,并且会在打印时修改TextNode.与其说是一个天真的实施不好.真的很遗憾......