Python SAX解析器:resolveEntity

Python SAX解析器:resolveEntity,python,xml,sax,entityresolver,Python,Xml,Sax,Entityresolver,我很难弄清楚如何将自己的ResolveEntityHandler绑定到SAX解析器。就这样。但不幸的是,我无法在那里重现结果 当我运行下面的代码时,它实际上是从前面的答案复制的,刚刚更新到Python 3 import io import xml.sax from xml.sax.handler import ContentHandler # Inheriting from EntityResolver and DTDHandler is not necessary class TestHan

我很难弄清楚如何将自己的ResolveEntityHandler绑定到SAX解析器。就这样。但不幸的是,我无法在那里重现结果

当我运行下面的代码时,它实际上是从前面的答案复制的,刚刚更新到Python 3

import io
import xml.sax
from xml.sax.handler import ContentHandler

# Inheriting from EntityResolver and DTDHandler is not necessary
class TestHandler(ContentHandler):

    # This method is only called for external entities. Must return a value.
    def resolveEntity(self, publicID, systemID):
        print ("TestHandler.resolveEntity(): %s %s" % (publicID, systemID))
        return systemID

    def skippedEntity(self, name):
        print ("TestHandler.skippedEntity(): %s" % (name))

    def unparsedEntityDecl(self, name, publicID, systemID, ndata):
        print ("TestHandler.unparsedEntityDecl(): %s %s" % (publicID, systemID))

    def startElement(self, name, attrs):
        summary = attrs.get('summary', '')
        print ('TestHandler.startElement():', summary)

def main(xml_string):
    try:
        parser = xml.sax.make_parser()
        curHandler = TestHandler()
        parser.setContentHandler(curHandler)
        parser.setEntityResolver(curHandler)
        parser.setDTDHandler(curHandler)

        stream = io.StringIO(xml_string)
        parser.parse(stream)
        stream.close()
    except xml.sax.SAXParseException as e:
        print ("ERROR %s" % e)

XML = """<!DOCTYPE test SYSTEM "test.dtd">
<test summary='step: &num;'>Entity: &not;</test>
"""

main(XML)
我得到的是

TestHandler.startElement(): step: 
TestHandler.skippedEntity(): not

Process finished with exit code 0
因此,我的问题是:

  • 为什么从未调用过
    resolveEntity
  • 如何将ResolveEntityHandler绑定到解析器

  • 您所看到的与以下内容有关:

    在版本3.7.1中更改:默认情况下,SAX解析器不再处理一般的外部实体以提高安全性。在此之前,解析器创建网络连接以从文件系统获取DTD和实体的远程文件或加载的本地文件。可以使用解析器对象和参数
    feature\u external\ges
    上的方法
    setFeature()
    再次启用该功能

    要获得与早期版本相同的行为,请添加以下行:

    from xml.sax.handler import feature_external_ges
    
    和(在
    主功能中)

    from xml.sax.handler import feature_external_ges
    
    parser.setFeature(feature_external_ges, True)