python小白-day6 xml处理模块

xml处理模块

xml是实现不同语言或程序之间进行数据交换的协议，跟json差不多，但json使用起来更简单，不过，古时候，在json还没诞生的黑暗年代，大家只能选择用xml呀，至今很多传统公司如金融行业的很多系统的接口还主要是xml。

xml的格式如下，就是通过<>节点来区别数据结构的:

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<?xml version="1.0"?> <data>     <country name="Liechtenstein">         <rank updated="yes">2</rank>         <year>2008</year>         <gdppc>141100</gdppc>         <neighbor name="Austria" direction="E"/>         <neighbor name="Switzerland" direction="W"/>     </country>     <country name="Singapore">         <rank updated="yes">5</rank>         <year>2011</year>         <gdppc>59900</gdppc>         <neighbor name="Malaysia" direction="N"/>     </country>     <country name="Panama">         <rank updated="yes">69</rank>         <year>2011</year>         <gdppc>13600</gdppc>         <neighbor name="Costa Rica" direction="W"/>         <neighbor name="Colombia" direction="E"/>     </country> </data>

xml协议在各个语言里的都 是支持的，在python中可以用以下模块操作xml

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import xml.etree.ElementTree as ET   tree = ET.parse("xmltest.xml") root = tree.getroot() print(root.tag)   #遍历xml文档 for child in root:     print(child.tag, child.attrib)     for i in child:         print(i.tag,i.text)   #只遍历year 节点 for node in root.iter('year'):     print(node.tag,node.text)

修改文件内容

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import xml.etree.ElementTree as ET   tree = ET.parse("xmltest.xml") root = tree.getroot() print(root.tag) for node in root.iter('year'):     new_year = int(node.text) + 1     node.text = str(new_year)     node.set("updated","yes")   tree.write("xmltest_out.xml")

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删除文件内容：删除rank>50的country

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import xml.etree.ElementTree as ET   tree = ET.parse("xmltest.xml") root = tree.getroot() for country in root.findall('country'):    rank = int(country.find('rank').text)    if rank > 50:      root.remove(country) tree.write('output.xml')

自己创建xml文档

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import xml.etree.ElementTree as ET     new_xml = ET.Element("namelist") name = ET.SubElement(new_xml,"name",attrib={"enrolled":"yes"}) age = ET.SubElement(name,"age",attrib={"checked":"no"}) sex = ET.SubElement(name,"sex") age.text = '33' sex.text = 'male' name2 = ET.SubElement(new_xml,"name",attrib={"enrolled":"no"}) age = ET.SubElement(name2,"age") sex = ET.SubElement(name2,"sex") age.text = '19' sex.text = 'fmale'   et = ET.ElementTree(new_xml) #生成文档对象 et.write("test.xml", encoding="utf-8",xml_declaration=True)   ET.dump(new_xml) #打印生成的格式

来自为知笔记(Wiz)