Python与XML操作
一、介绍
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，在json还没诞生的黑暗年代，大家只能选择用xml呀，所以，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。
二、结构
xml的格式如下，就是通过<>节点来区别数据结构的:
<?xml version="1.0"?> <data> <country name="china"> <rank updated="yes">2</rank> <year>2008</year> <gdppc>141100</gdppc> <neighbor name="english" direction="E"/> <neighbor name="Switzerland" direction="W"/> </country> <country name="French"> <rank updated="yes">5</rank> <year>2011</year> <gdppc>59900</gdppc> <neighbor name="Malaysia" direction="N"/> </country> <country name="Italy"> <rank updated="yes">69</rank> <year>2011</year> <gdppc>13600</gdppc> <neighbor name="Costa Rica" direction="W"/> <neighbor name="Colombia" direction="E"/> </country> </data>
三、在Python中使用XML
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
1、遍历XML
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)
2、修改和删除xml文档内容
mport 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‘)
3、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
