尝试以下代码:

import lxml.etree
from gzip import open as gopen

class GroupDictTarget(object):
    def __init__(self, d):
        self.d = d
    def start(self, tag, attrib):
        if tag == 'group':
            self.group = self.d[attrib['from'], attrib['to']] = []
        elif tag == 'link':
            self.group.append(attrib['target'])
    def close(self):
        pass

def extractTargets(fin):
    with gopen(fin) as xml:
        targets = {}
        parser = lxml.etree.XMLParser(target=GroupDictTarget(targets))
        lxml.etree.parse(xml, parser)
        return targets

xml.parsers.expat

import xml.parsers.expat
from gzip import open as gopen

class GroupDictTarget(object):
    # Same as above

def extractTargets(fin):
    targets = {}
    p = xml.parsers.expat.ParserCreate()
    p.StartElementHandler = GroupDictTarget(targets).start
    with gopen(fin) as f:
        p.ParseFile(f)
    return targets

xml.sax

import xml.sax
from gzip import open as gopen

class GroupDictTarget(object):
    # Same as above

def extractTargets(fin):
    targets = {}
    handler = xml.sax.handler.ContentHandler()
    handler.startElement = GroupDictTarget(targets).start
    with gopen(fin) as f:
        xml.sax.parse(f, handler)
    return targets