使用python xml.sax解析XML实体

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使用xml.sax用python解析XML，但是我的代码无法捕获实体.为什么在以下情况中不跳过skipEntity()或resolveEntity()报告:

Parsing XML with python using xml.sax, but my code fails to catch Entities. Why doesn't skippedEntity() or resolveEntity() report in the following:

import os import cStringIO import xml.sax from xml.sax.handler import ContentHandler,EntityResolver,DTDHandler #Class to parse and run test XML files class TestHandler(ContentHandler,EntityResolver,DTDHandler): #SAX handler - Entity resolver def resolveEntity(self,publicID,systemID): print "TestHandler.resolveEntity: %s %s" % (publicID,systemID) def skippedEntity(self, name): print "TestHandler.skippedEntity: %s" % (name) def unparsedEntityDecl(self,publicID,systemID,ndata): print "TestHandler.unparsedEntityDecl: %s %s" % (publicID,systemID) def startElement(self,name,attrs): # name = string.lower(name) summary = '' + attrs.get('summary','') arg = '' + attrs.get('arg','') print 'TestHandler.startElement(), %s : %s (%s)' % (name,summary,arg) def run(xml_string): try: parser = xml.sax.make_parser() stream = cStringIO.StringIO(xml_string) curHandler = TestHandler() parser.setContentHandler(curHandler) parser.setDTDHandler( curHandler ) parser.setEntityResolver( curHandler ) parser.parse(stream) stream.close() except (xml.sax.SAXParseException), e: print "*** PARSER error: %s" % e; def main(): try: XML = "<!DOCTYPE page[ <!ENTITY num 'foo'> ]><test summary='step: &num;'>Entity: &not;</test>" run(XML) except Exception, e: print 'FATAL ERROR: %s' % (str(e)) if __name__== '__main__': main()

运行时，我看到的只是:

When run, all I see is:

TestHandler.startElement(), step: foo () *** PARSER error: <unknown>:1:36: undefined entity

为什么我看不到##的resolveEntity打印?或跳过的条目打印为& not ??

Why don't I see the resolveEntity print for &num; or the skipped entry print for &not;?

推荐答案

我认为只能为外部DTD调用resolveEntity和skippedEntity.我可以通过修改XML来使其工作.

I think resolveEntity and skippedEntity are only called for external DTDs. I got this to work by modifying the XML.

XML = """<?xml version="1.0" encoding="utf-8" ?> <!DOCTYPE test SYSTEM "external.dtd" > <test summary='step: &foo; &bar;'>Entity: &not;</test> """

external.dtd 包含两个简单的实体声明.

The external.dtd contains two simple entity declarations.

<!ENTITY foo "bar"> <!ENTITY bar "foo">

此外，我摆脱了resolveEntity.

Also, I got rid of resolveEntity.

此输出-

TestHandler.startElement(), test : step: bar foo () TestHandler.skippedEntity: not

希望这会有所帮助.