python—xml读写—minidom and etree

test.xml

<?xml version="1.0" encoding="UTF-8"?> <employees>   <employee id="0">     <name>Liu</name>    <age>30</age>  </employee>  <employee id="1">     <name>John</name>    <age>20</age>  </employee> </employees>

1. minidom

from xml.dom import minidom  from codecs import openif __name__ == '__main__':    #用xml.dom.minidom读xml    doc=minidom.parse('test.xml')    root=doc.documentElement #得到根节点——employees    employees=root.getElementsByTagName('employee') #根据名字来查找子elements    for employee in employees:        print ("id:"+employee.getAttribute('id')) #获得属性值        name=employee.getElementsByTagName('name')[0] #childNodes返回所有的子Nodes，其中所有的文本均为textNode，包括元素间的‘\n\r’和空格均        print(name.nodeName+":"+name.childNodes[0].nodeValue) #nodeValue是结点的值，只对textNode有效        age=employee.getElementsByTagName('age')[0]        print(age.nodeName+":"+age.childNodes[0].data) #对于textNode，得到文本内容也可以使用.data            #用xml.dom.minidom写xml    impl=minidom.getDOMImplementation()    doc=impl.createDocument(None, 'employees', None) #创建根节点——employees    root=doc.documentElement    employee=doc.createElement('employee') #创建employee节点    employee.setAttribute('id', '0') #设置id属性    root.appendChild(employee)        namenode=doc.createElement('name') #创建name节点    nametext=doc.createTextNode('刘') #创建textnode    namenode.appendChild(nametext)    employee.appendChild(namenode)        agenode=doc.createElement('age')    agetext=doc.createTextNode('30')    agenode.appendChild(agetext)    employee.appendChild(agenode)        f=open('write.xml','w',encoding='utf-8')    #addindent表示子元素缩进，newl='\n'表示元素间换行，encoding='utf-8'表示生成的xml的编码格式（<?xml version="1.0" encoding="utf-8"?>）    doc.writexml(f, addindent='  ', newl='\n', encoding='utf-8')

输出结果：

id:0name:Liuage:30id:1name:Johnage:20

write.xml:

<?xml version="1.0" encoding="utf-8"?><employees>  <employee id="0">    <name>刘</name>    <age>30</age>  </employee></employees>

2. etree

from xml.etree import ElementTree#打印节点信息def print_node(node):    print "-------------------------------"    print "attrib:%s" %node.attrib #属性的字典    print "id:%s" %node.attrib['id'] #指定的属性值    for key,value in node.items(): #items:属性(name, value)对儿        print "%s:%s" %(key,value)    for child in node:        print "tag:%s" %child.tag        print "text:%s" %child.text#读xmldef readxml(text='',xmlfile=''):    #root=ElementTree.parse('test.xml').getroot() #加载指定文件获得根节点    root=ElementTree.fromstring(text) #加载指定字符串获得根节点        employees=root.iter('employee') #通过iter(tag=None)获取element    for employee in employees:        print_node(employee)        for employee in root.findall('employee'): #findall:匹配的直接子节点        print "-------------------------------"        age=employee.find('age').text #find:第一个匹配的        id=employee.get('id') #得到属性值        print age,id        #更改xmldef updatexml(text='',xmlfile=''):    tree=ElementTree.parse(xmlfile) #加载指定文件    root=tree.getroot() #获得根节点    for age in root.iter('age'): #获得所有age节点        newage=int(age.text)+1        age.text=str(newage)        age.set('updated','yes') #设置属性-值            name=root[0].find('name')    root[0].remove(name) #移除节点    #创建节点    employee=ElementTree.Element('employee',{'id':'99'}) #Element(tag, attrib={}, **extra)    name=ElementTree.SubElement(employee, 'name') #SubElement(parent, tag, attrib={}, **extra)    name.text='新'    age=ElementTree.SubElement(employee,'age')    age.text='99'    root.append(employee)        #write(file, encoding="us-ascii", xml_declaration=None, default_namespace=None, method="xml")    tree.write('updated.xml',encoding='utf-8')        if __name__ == '__main__':    readxml(open('test.xml').read())    updatexml('','test.xml')

输出结果：

-------------------------------attrib:{'id': '0'}id:0id:0tag:nametext:Liutag:agetext:30-------------------------------attrib:{'id': '1'}id:1id:1tag:nametext:Johntag:agetext:20-------------------------------30 0-------------------------------20 1

update.xml:

<employees>   <employee id="0">     <age updated="yes">31</age>  </employee>  <employee id="1">     <name>John</name>    <age updated="yes">21</age>  </employee> <employee id="99"><name>新</name><age>99</age></employee></employees>

用SubElement好像没法换行？