Python解析XML文档

import xml.etree.ElementTree as etree
from xml.etree.ElementTree import ElementTree 
from xml.etree.ElementTree import Element

def is_info_in_xml( xml_filename):
	'''精确检查XML文档中被查找信息是否存在'''
	info_exists = False
	xml_document = etree.parse(xml_filename)
	root = xml_document.getroot()           # 获取根元素
	# print('xml file root:', root)   # 获取根名称
	# print('root:%s' % root )  # 获取根元素的属性集
	# print('%s %s="%s"' % (root.tag, root.tag, root.attrib) )  # 获取根元素的属性集
	# print('root len:', len(root))   # 获取根元素的长度（也就是根元素下的子元素的个数）
	# 检查root节点下的所有子节点
	for softwarelist in root:		# 处理下一级子节点SoftwareList
		# print('\t%s' % softwarelist.tag, end = ' ')
		for attrname in softwarelist.attrib:
			# print('%s="%s"' % (attrname, softwarelist.attrib[attrname]), end = ' ')  # 获取元素的属性集
			pass
		# print()
		for group in softwarelist:	# 处理下一级子节点Group
			# print('\t%s' % group.tag, end = ' ')
			for attrname in group.attrib:
				# print('%s="%s"' % (attrname, group.attrib[attrname]), end = ' ')  	# 获取元素的属性集
				pass
			# print()
			for software in group:	# 处理下一级子节点Software
				# print('\t\t%s' % software.tag)
				for attrname in software.attrib:
					# print('\t\t\t%s="%s"' % (attrname, software.attrib[attrname]))  	# 获取元素的属性集
					if '查找字符串' in software.attrib[attrname]:
						info_exists = True
				# print()
				
	return info_exists