使用lxml在python中解析多个名称空间XML

Question

<?xml-stylesheet href="/Style Library/st/xslt/rss2.xsl" type="text/xsl" media="screen" ?>
<rss version="2.0" xmlns:atom="http://www.w3.org/2005/Atom" xmlns:ta="http://www.smartraveller.gov.au/schema/rss/travel_advisories/" xmlns:dc="http://purl.org/dc/elements/1.1/">

  <channel>
    <title>Travel Advisories</title>
    <link>http://smartraveller.gov.au/countries/</link>
    <description>the Australian Department of Foreign Affairs and Trade's Smartraveller advisory service</description>
    <language>en</language>
    <webMaster>[email protected]</webMaster>
    <copyright>Copyright Commonwealth of Australia 2011</copyright>
    <ttl>60</ttl>
    <atom:link href="http://smartraveller.gov.au/countries/Documents/index.rss" rel="self" type="application/rss+xml" />
    <generator>zcms</generator>
    <image>
      <title>Advice</title>
      <link>http://smartraveller.gov.au/countries/</link>
      <url>/Style Library/st/images/dfat_logo_small.gif</url>
    </image>
    <item>
      <title>Czech Republic</title>
      <description>This travel advice has been reviewed. The level of our advice has not changed. Exercise normal safety precautions in the Czech Republic.</description>
      <link>http://smartraveller.gov.au/Countries/europe/eastern/Pages/czech_republic.aspx</link>
      <pubDate>26 Oct 2018 05:25:14 GMT</pubDate>
      <guid isPermaLink="false">cdbcc3d4-3a89-4768-ac1d-0221f8c99227 GMT</guid>
      <ta:warnings>
        <dc:coverage>Czech Republic</dc:coverage>
        <ta:level>2/5</ta:level>
        <dc:description>Exercise normal safety precautions</dc:description>
      </ta:warnings>
  </item>

我想在<ta:level>中为每个项目提取q​​azxswpoi的值。我试过现有的在线解决方案，但对我来说没什么用。基本上，我的xml包含多个名称空间。

<warning>

Answer 1

XML有多个名称空间，但您需要担心的唯一名称空间是

req = requests.request('GET', "https://smartraveller.gov.au/countries/documents/index.rss")
a = str(req.text).encode()
tree = etree.fromstring(a)

ns = {'TravelAd': 'https://smartraveller.gov.au/countries/documents/index.rss',
          'ta': 'http://www.smartraveller.gov.au/schema/rss/travel_advisories/'}

    e = tree.findall('{0}channel/{0}item/{0}warnings/{0}level'.format(ns))
    for i in e:
        print(i.text)

。

这是因为命名空间中目标路径中唯一的元素是http://www.smartraveller.gov.au/schema/rss/travel_advisories/和ta:level。

例...

ta:warning

打印...

from lxml import etree
import requests

req = requests.request('GET', "https://smartraveller.gov.au/countries/documents/index.rss")
a = str(req.text).encode()

tree = etree.fromstring(a)

ns = {'ta': 'http://www.smartraveller.gov.au/schema/rss/travel_advisories/'}

e = tree.findall('channel/item/ta:warnings/ta:level', ns)
for i in e:
    print(i.text)

如果你想要一个列表，考虑从

2/5
2/5
4/5
2/5
...and so on

切换到findall() ......

xpath()

打印...

e = tree.xpath('channel/item/ta:warnings/ta:level/text()', namespaces=ns)
print(e)