20180209-xml模块

xml的用法操作如下：

　　xml格式如下：

<?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协议在各个语言中都是支持的，在python中可以使用如下模块操作xml

import xml.etree.ElementTree as ET  

tree = ET.parse('xmltest.xml')
root = tree.getroot()
print(root.tag)
# 输出
# data                              

# 遍历xml文档
for child in root:
    print(child.tag,child.attrib)
# 输出
# country {'name': 'Liechtenstein'}
# country {'name': 'Singapore'}
# country {'name': 'Panama'}        

for node in root:
    for child in node:
        print(child.tag,child.text)
# 输出
# rank 2
# year 2008
# gdppc 141100
# neighbor None
# neighbor None                     

# rank 5
# year 2011
# gdppc 59900
# neighbor None                     

# rank 69
# year 2011
# gdppc 13600
# neighbor None
# neighbor None                     

# 只遍历year节点
for node in root.iter('year'):
    print(node.tag,node.text)       

# 输出
# year 2008
# year 2011
# year 2011                         

　　修改和删除xml文档

# 修改
for node in root.iter('year'):
    new_year = int(node.text) + 1
    node.text = str(new_year)
    node.set('update','yes')
tree.write('xmltest.xml')        

# 只遍历year节点
for node in root.iter('year'):
    print(node.tag,node.text)
# 输出
# year 2009
# year 2012
# year 2012

# 删除node
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

import xml.etree.ElementTree as ET                            

new_xml = ET.Element('namelist')
name = ET.SubElement(new_xml,'name',attrib={'enrolld': 'yes'})
age = ET.SubElement(name,'age',attrib={'checed': 'no'})
sex = ET.SubElement(name,'sex')
sex.text = '男'                                                

name2 = ET.SubElement(new_xml,'name',attrib={'enrolld': 'no'})
age = ET.SubElement(name2,'age')
age.text = ''                                               

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) #打印生成格式