如果第一个XML父标记缺少子标记,则Python XPath和ElementTree不起作用

时间:2019-06-05 17:40:27

标签: python xpath elementtree

我目前正在使用Python通过ElementTree库和XPath将XML文件转换为CSV格式。如果第一个父母标签的所有子标签(名字,姓氏和地址)都存在,那么我的代码将起作用,但是我收到一条错误消息

  

儿童索引超出范围

当第一个人缺少子标签时(只有名字和姓氏存在)。

我可以编写哪些代码来绕过此错误消息?这是我第一次使用XPath,如何向其中添加if语句?还是我应该使用其他东西?

这是我的XML文件的样子:

<?xml version="1.0" encoding="utf-8"?>
<Members>
    <Person>
      <FirstName>JANE</FirstName>
      <LastName>DOE</LastName>
    </Person>
    <Person>
      <FirstName>JOHN</FirstName>
      <LastName>DOE</LastName>
      <Address>
        <Address1>123 Straw Street</Address1>
        <Address2></Address2>
        <City>Apple</City>
        <State>Test</State>
        <ZipCode>123456    </ZipCode>
      </Address>
    </Person>
</Members>

当前的Python代码:

import  csv
import xml.etree.ElementTree as ET

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

xml_data_to_csv =open('OutputStack.csv','w')

Csv_writer=csv.writer(xml_data_to_csv)
list_head=[]

count=0
for element in root.findall('Person'):
    person = []

    #Get head by tag
    if count == 0:
       FirstName = element.find('FirstName').tag
       list_head.append(FirstName)

       LastName = element.find('LastName').tag
       list_head.append(LastName)

       Address = element[2].tag
       list_head.append(Address)

       Csv_writer.writerow(list_head)
       count = count +1

    #get child node
    FirstName = element.find('FirstName').text
    person.append(FirstName)

    LastName = element.find('LastName').text
    person.append(LastName)

    person.append([e.text for e in element.findall('Address//')])

    #Write List_nodes to csv
    Csv_writer.writerow(person)
xml_data_to_csv.close()

1 个答案:

答案 0 :(得分:1)

我认为标题应该是预定义的。我怀疑您的CSV导入后端是否接受任何格式。

import  csv
import xml.etree.ElementTree as ET

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

xml_data_to_csv =open('out.csv','w')

Csv_writer=csv.writer(xml_data_to_csv)
list_head=['FirstName', 'LastName', 'Address']
Csv_writer.writerow(list_head)

for element in root.findall('Person'):
    person = []

    #get child node
    FirstName = element.find('FirstName').text
    person.append(FirstName)

    LastName = element.find('LastName').text
    person.append(LastName)

    person.append([e.text for e in element.findall('Address//')])

    #Write List_nodes to csv
    Csv_writer.writerow(person)
xml_data_to_csv.close()

否则,您可以处理异常或检查存在多少这样的元素

if len(element) > 2:
    head_list.append(element[2])
    continue

预先初始化head_list = [None] * 3 #len(element),并在for循环期间收集标头(作为显示)和人员,然后在末尾编写所有内容。我不推荐那条路线。