python xml 模块

xml 处理：
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，
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。
文档格式：他是通过<> 节点来区别数据结构的：

文档格式

<?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>　　

#python操作xml协议：
import xml.etree.ElementTree as ET

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)


#修改和删除xml文档内容
import xml.etree.ElementTree as ET

tree = ET.parse("xmltest.xml")
root = tree.getroot()

# 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')

# 自己创建xml文档
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")
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