网络抓取python中的xml页面？

Question

我很困惑如何从给定的 xml 页面中刮取所有链接（仅包含字符串“mp3”）。以下代码只返回空括号：

# Import required modules 
from lxml import html 
import requests 
  
# Request the page 
page = requests.get('https://feeds.megaphone.fm/darknetdiaries') 
  
# Parsing the page 
# (We need to use page.content rather than  
# page.text because html.fromstring implicitly 
# expects bytes as input.) 
tree = html.fromstring(page.content)   
  
# Get element using XPath 
buyers = tree.xpath('//enclosure[@url="mp3"]/text()') 
print(buyers)

我使用@url 错了吗？

我要找的链接：

任何帮助将不胜感激！

Answer 1

会发生什么？

以下 xpath 不起作用，正如您提到的，它使用了 @url 和 text()

//enclosure[@url="mp3"]/text()

解决方案

任何url中的属性//enclosure都应该包含mp3，然后返回/@url

更改这一行：

buyers = tree.xpath('//enclosure[@url="mp3"]/text()') 

到

buyers = tree.xpath('//enclosure[contains(@url,"mp3")]/@url') 

输出

['https://www.podtrac.com/pts/redirect.mp3/traffic.megaphone.fm/ADV9231072845.mp3?updated=1610644901',
 'https://www.podtrac.com/pts/redirect.mp3/traffic.megaphone.fm/ADV2643452814.mp3?updated=1609788944',
 'https://www.podtrac.com/pts/redirect.mp3/traffic.megaphone.fm/ADV5381316822.mp3?updated=1607279433',
 'https://www.podtrac.com/pts/redirect.mp3/traffic.megaphone.fm/ADV9145504181.mp3?updated=1607280708',
 'https://www.podtrac.com/pts/redirect.mp3/traffic.megaphone.fm/ADV4345070838.mp3?updated=1606110384',
 'https://www.podtrac.com/pts/redirect.mp3/traffic.megaphone.fm/ADV8112097820.mp3?updated=1604866665',
 'https://www.podtrac.com/pts/redirect.mp3/traffic.megaphone.fm/ADV2164178070.mp3?updated=1603781321',
 'https://www.podtrac.com/pts/redirect.mp3/traffic.megaphone.fm/ADV1107638673.mp3?updated=1610220449',
...]

Answer 2

它不会直接回答您的问题，但您可以查看 BeautifulSoup 作为替代方案（并且它也可以选择在箍下使用 lxml）。

import lxml # early failure if not installed
from bs4 import BeautifulSoup
import requests 
  
# Request the page 
page = requests.get('https://feeds.megaphone.fm/darknetdiaries') 

# Parse
soup = BeautifulSoup(page.text, 'lxml')

# Find
#mp3 = [link['href'] for link in soup.find_all('a') if 'mp3' in link['href']]
# UPDATE - correct tag and attribute
mp3 = [link['url'] for link in soup.find_all('enclosure') if 'mp3' in link['url']]