使用etree Python解析xml

Question

對於這個XML

<locations>

    <location>
        <locationid>1</locationid>
        <homeID>281</homeID>
        <buildingType>Added</buildingType>
        <address>A</address>
        <address2>This is address2</address2>
        <city>This is city/city>
        <state>State here</state>
        <zip>1234</zip>
    </location>
    <location>
        <locationid>2</locationid>
        <homeID>81</homeID>
        <buildingType>Added</buildingType>
        <address>B</address>
        <address2>This is address2</address2>
        <city>This is city/city>
        <state>State here</state>
        <zip>1234</zip>
    </location>
    .
    .
    .
    .
    <location>
        <locationid>10</locationid>
        <homeID>21</homeID>
        <buildingType>Added</buildingType>
        <address>Z</address>
        <address2>This is address2</address2>
        <city>This is city/city>
        <state>State here</state>
        <zip>1234</zip>
    </location>
</locations>

我怎樣才能locationID的地址A ，使用etree 。

這是我的代碼，

import urllib2
import lxml.etree as ET

url="url for the xml"
xmldata = urllib2.urlopen(url).read()
# print xmldata
root = ET.fromstring(xmldata)
for target in root.xpath('.//location/address[text()="A"]'):
    print target.find('LocationID')

獲取輸出為None ，我在這里做什么錯？

Answer 1

首先，您的xml格式不正確。 發布時應多加注意，並盡量避免讓其他用戶修復您的數據。

您可以搜索前面的兄弟姐妹，例如：

import urllib2
import lxml.etree as ET

url="..."
xmldata = urllib2.urlopen(url).read()
root = ET.fromstring(xmldata)
for target in root.xpath('.//location/address[text()="A"]'):                                                                                                  
    for location in [e for e in target.itersiblings(preceding=True) if e.tag == "locationid"]:                                                                
        print location.text

或直接從xpath表達式中執行操作，例如：

import urllib2
import lxml.etree as ET

url="..."
xmldata = urllib2.urlopen(url).read()
root = ET.fromstring(xmldata)
print root.xpath('.//location/address[text()="A"]/preceding-sibling::locationid/text()')[0]

像這樣運行它們之一：

python2 script.py

產量：

1