在Python中浏览HTML DOM

Question

我正在寻找一个Python脚本(使用3.4.3),它从URL抓取一个HTML页面,并可以通过DOM来尝试查找特定元素.

我目前有这个:

#!/usr/bin/env python
import urllib.request

def getSite(url):
    return urllib.request.urlopen(url)

if __name__ == '__main__':
    content = getSite('http://www.google.com').read()
    print(content)

当我打印内容时,它会打印出整个html页面,这与我想要的内容很接近......虽然我希望能够在DOM中导航而不是将其视为一个巨大的字符串.

我还是Python的新手,但有多种其他语言的经验(主要是Java,C#,C++,C,PHP,JS).我之前用Java做过类似的事情,但想在Python中尝试一下.

任何帮助表示赞赏.干杯!

Answer 1

您可以使用许多不同的模块.例如,lxml或BeautifulSoup.

这是一个lxml例子:

import lxml.html

mysite = urllib.request.urlopen('http://www.google.com').read()
lxml_mysite = lxml.html.fromstring(mysite)

description = lxml_mysite.xpath("//meta[@name='description']")[0] # meta tag description
text = description.get('content') # content attribute of the tag

>>> print(text)
"Search the world's information, including webpages, images, videos and more. Google has many special features to help you find exactly what you're looking for."

一个BeautifulSoup例子:

from bs4 import BeautifulSoup

mysite = urllib.request.urlopen('http://www.google.com').read()
soup_mysite = BeautifulSoup(mysite)

description = soup_mysite.find("meta", {"name": "description"}) # meta tag description
text = description['content'] # text of content attribute

>>> print(text)
u"Search the world's information, including webpages, images, videos and more. Google has many special features to help you find exactly what you're looking for."

请注意如何BeautifulSoup返回unicode字符串,而lxml不是.根据需要,这可能有用/有害.