【发布时间】:2015-11-04 00:09:46
【问题描述】:
我一直在尝试使用 lxml 读取 xml 文件并替换类别和子类别标签之间的值。
我想将新的 xml 重定向到一个新文件。
data = """<xml>
<questionset author="Joee Foo"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns="http://www.escreeningz.com"
xsi:schemaLocation="http://www.escreeningz.com ../xsd/QuestionSet.xsd">
<question status="A" identifier="SampleQuestions.xml_1">
<classification>
<type>CONCEPTUAL</type>
<category>Core Java</category>
<subcategory>Exception Handling</subcategory>
<difficulty>2</difficulty>
</classification>
<tags>
<tag>Exception Hierarchy</tag>
<tag>Checked and Unchecked exceptions</tag>
<tag>Finally Block</tag>
</tags>
<preface>
<section order="1" type="STANDARD">
<value><![CDATA[Which of the statements regarding exceptions in Java are true?]]></value>
</section>
</preface>
<answers>
<answer correct="false" score="-4">
<value><![CDATA[Checked exceptions extend java.lang.RuntimeException.
]]></value>
<explain>It is uncheked exception that extend java.lang.Runtime;not checked</explain>
</answer>
<answer correct="true" score="5">
<value><![CDATA[The base class for all Exceptions and Errors is java.lang.Throwable.
]]></value>
</answer>
<answer correct="true" score="5">
<value><![CDATA[Any method that might throw a checked exception like java.io.IOException must either declare
the exception using the throws keyword or handle the exception with an appropriate try/catch.
]]></value>
</answer>
<answer correct="true" score="2">
<value><![CDATA[If you use a finally block, it will always be invoked regardless of whether an exception in the corresponding try is thrown or not
and regardless of whether a thrown exception is caught or not as long as the JVM is running.
]]></value>
</answer>
<answer correct="false" score="-4">
<value><![CDATA[All catch blocks must be ordered as general caught first to specific caught last]]></value>
<explain>All catch blocks must be ordered from specific to general</explain>
</answer>
</answers>
</question>
</questionset>
</xml>
"""
# csv to xml conversion
import sys
import os
import csv
import xml.etree.ElementTree as ET
from lxml import etree
from StringIO import StringIO
from lxml.etree import Element
stream = StringIO(data)
context = etree.iterparse(stream, events=("start", ))
现在,当我尝试从标签之间提取值时,它返回一个空列表。 :(
for action,elem in context:
for child in elem.findall('{http://www.escreeningz.com}category'):
print child.attrib
Result is : {}
当我运行以下代码时,它会正确返回标签:
for action,elem in context:
for child in elem.findall('{http://www.escreeningz.com}category'):
print child.tag
Result: {http://www.escreeningz.com}category
我在这里错过了什么吗?
我终于要换了
<category>Core Java</category>
与
<category>SQL</category>
【问题讨论】:
-
category元素没有属性,所以findall找到category元素,其中没有属性可以找到,所以返回正确。
-
有没有办法找到类别标签之间的文字?我可能需要迭代才能在多个标签之间查找文本。但是,这是我认为的第二步。
-
例如,打印 child.text。我建议查看 lxml 文档并阅读有关 XML 结构的信息。
标签: python xml-parsing lxml