import xml.etree.ElementTree as ET

new_xml=ET.Element('personinfolist')  #最外面的标签名
personinfo=ET.SubElement(new_xml,'personinfo',attrib={'enrolled':'aaa'}) #对应的参数是：父级标签是谁，当前标签名，当前标签属性与值
name=ET.SubElement(personinfo,'name')
name.text='xaoming'
age=ET.SubElement(personinfo,'age',attrib={'checked':'yes'})
age.text='23'

personinfo2=ET.SubElement(new_xml,'personinfo',attrib={'enrolled':'bbb'})
name=ET.SubElement(personinfo2,'name')
name.text='xaokong'
age=ET.SubElement(personinfo2,'age',attrib={'checked':'no'})
age.text='20'

et=ET.ElementTree(new_xml)
et.write('text1.xml',encoding='utf-8',xml_declaration=True)#生成text1.xml

import xml.etree.ElementTree as ET
tree=ET.parse('text1.xml')
root=tree.getroot()
print(root.tag)
#遍历 xml 文档
for i in root:
  print(i.tag,i.attrib)  # tag是指标签名，attrib 是指标签里的属性，text 是指标签内容
  for j in i:
    print(j.tag,j.attrib,j.text)
    for k in j:
      print(k.tag,k.attrib,k.text)
#只遍历 year 标签
for w in root.iter('year'): #只遍历指定标签
  print(w.tag,w.text)

import xml.etree.ElementTree as ET
tree=ET.parse('text1.xml')
root=tree.getroot()
print(root.tag)
#修改 xml
for node in root.iter('year'): #要修改的标签
  new_year=int(node.text)+1
  node.text=str(new_year)
  node.set('updsted_by','kong') #给这个标签（year）添加新的属性 key：value
tree.write('text1.xml')   #再吧数据写回去

import xml.etree.ElementTree as ET
tree=ET.parse('text1.xml')
root=tree.getroot()
for country in root.findall('country'):  #会取这个标签所有的数据
  rank=int(country.find('rank').text)
  if rank > 50:
    root.remove(country)  #删除数据
tree.write('output.xml') #再把数据写回文件