Python(xml模块)

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，不过，古时候，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。

xml的格式如下，就是通过<>节点来区别数据结构的:

xml_test文件，xml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>

xml协议在各个语言里的都 是支持的，在python中可以用以下模块操作xml：

import xml.etree.ElementTree as ET

tree = ET.parse("xml_test")
root = tree.getroot()
print(root.tag)#根标签


print("
")
#遍历xml文档
for child in root:#遍历child
    print(child.tag, child.attrib)#标签，属性

print("
")
#遍历xml文档
for child in root:#遍历child
    #print(child.tag, child.attrib)#标签，属性
    for i in child:#遍历child中内容
        print(i.tag,i.text) #neighbor是None,因为它是自闭合标签

执行结果：

data


country {'name': 'Liechtenstein'}
country {'name': 'Singapore'}
country {'name': 'Panama'}


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

Process finished with exit code 0

neighbor是None,因为它是自闭合标签

import xml.etree.ElementTree as ET

tree = ET.parse("xml_test")
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("xml_test.xml")

# 删除node
for country in root.findall('country'):#根里面找country标签
    rank = int(country.find('rank').text)
    if rank > 50:#50名开外的删除
        root.remove(country)

tree.write('output.xml')

修改xml_test文件，和删除其中节点。

创建xml

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

生成test.xml

<?xml version='1.0' encoding='utf-8'?>
<namelist><name enrolled="yes"><age checked="no" /><sex>33</sex></name><name enrolled="no"><age>19</age></name></namelist>

只需了解