Python函数和常用模块-XML处理

xml文件：

<?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>>
```


增删改查：

```
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
for node in root.iter('year'):
    new_year = int(node.text) + 1
    node.text = str(new_year)
    node.set("updated","yes")
tree.write("xmltest.xml")
#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')
```
自己生成XML：

```
import xml.etree.ElementTree as ET
#生成xml
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")
sex.text = '33'
name2 = ET.SubElement(new_xml,"name",attrib={"enrolled":"no"})
age = ET.SubElement(name2,"age")
age.text = '19'
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
```