python学习，day5：内置模块（xml文件的创建和修改）

创建

# coding=utf-8
# Author: RyAn Bi
import xml.etree.ElementTree as ET
new_xml = ET.Element('namelist')    #根节点
personinfo = ET.SubElement(new_xml , 'personinfo', attrib={"enrolled": "yes"})  #new_xml下的子节点，叫personinfo
name = ET.SubElement(personinfo,'name')
age = ET.SubElement(personinfo, 'age')  #personinfo 下的子节点，叫age
sex = ET.SubElement(personinfo, 'sex')  #personinfo下的子节点，叫sex
name.text = 'bijibin'
age.text = '33'     #给age赋值
personinfo2 = ET.SubElement(new_xml , 'personinfo', attrib={"enrolled": "yes"})
name = ET.SubElement(personinfo2,'name', attrib={"enrolled": "yes"})  #new_xml下的子节点，叫personinfo2
age = ET.SubElement(personinfo2,'age')  #personinfo2 下的子节点，叫age
sex = ET.SubElement(personinfo2,'sex')  #personinfo2 下的子节点，叫sex
name.text='ryan'
age.text = '11'     #给age赋值

et = ET.ElementTree(new_xml) #生成文档对象

et.write('test.xml', encoding='utf-8', xml_declaration = True)   #声明格式和版本，写入test.xml
ET.dump(new_xml)    #打印生成格式

　　修改

import xml.etree.ElementTree as et
tree = et.parse('xmltest.xml')
root = tree.getroot()

# for node in root.iter('year'):     #修改year
#     new_year = int (node.text)+1    #每年都＋1
#     node.text = str(new_year)       # 把新的值附上去
#     node.set('updated','yes')      #给year增加一个属性
#
# tree.write('xmltest.xml')          #写回原文件

for country in root.findall('country'):    #查找当前element的孩子的属于某个tag的elemen
     rank = int(country.find('rank').text)     #找到country中rank文档
     if rank > 50:                             #找到＞50的
         root.remove(country)                  #删除这个country

tree.write('output.xml')                        #输出到新的xml

　　处理

# coding=utf-8
# Author: RyAn Bi
import xml.etree.ElementTree as ET   #导入包

tree = ET.parse('xmltest.xml')   #导入要处理的文件
root = tree.getroot()      #定义根目录
print(root)
print(root.tag)

for child in root:
    print(child.tag,child.attrib)
    for i in child:
        print(i.tag,i.attrib,i.text)  #打印标签，打印属性，打印文档
        for j in i:
            print(j.tag,j.attrib,j.text)
for node in root.iter('year'):
    print(node.tag,node.text)