Scraping/Parsing Google search results in Ruby

问题:

Assume I have the entire HTML of a Google search results page. Does anyone know of any existing code (Ruby?) to scrape/parse the first page of Google search results? Ideally it would handle the Shopping Results and Video Results sections that can spring up anywhere.

If not, what's the best Ruby-based tool for screenscraping in general?

To clarify: I'm aware that it's difficult/impossible to get Google search results programmatically/API-wise AND simply CURLing results pages has a lot of issues. There's concensus on both of these points here on stackoverflow. My question is different.

回答1:

This should be very simple thing, have a look at Screen Scraping with ScrAPI screen cast by Ryan Bates. You still can do without scraping libs, just stick to simple things like nokogiri.

Update:

From nokogiri's documentation:

  require 'nokogiri'
  require 'open-uri'

  # Get a Nokogiri::HTML:Document for the page we’re interested in...

  doc = Nokogiri::HTML(open('http://www.google.com/search?q=tenderlove'))

  # Do funky things with it using Nokogiri::XML::Node methods...

  ####
  # Search for nodes by css
  doc.css('h3.r a.l').each do |link|
    puts link.content
  end

  ####
  # Search for nodes by xpath
  doc.xpath('//h3/a[@class="l"]').each do |link|
    puts link.content
  end

  ####
  # Or mix and match.
  doc.search('h3.r a.l', '//h3/a[@class="l"]').each do |link|
    puts link.content
  end

回答2:

I'm unclear as to why you want to be screen scraping in the first place. Perhaps the REST search API would be more appropriate? It will return the results in JSON format, which will be much easier to parse, and save on bandwidth. For example, if your search was 'foo bar', you could just send a GET request to http://ajax.googleapis.com/ajax/services/search/web?v=1.0&q=foo+bar and handle the response.

For more information, see this blog post or the official documentation.

回答3:

I would suggest httparty + google ajax search api

回答4:

Scrapping has became harder and harder as Google keep changing while expanding how the results are structured (Rich snippets, knowledge graph, direct answer, etc.), we built a service that handle part of this complexity and we do have a Ruby library. It's pretty straightforward to use:

query = GoogleSearchResults.new q: "coffee"

# Parsed Google results into a Ruby hash
hash_results = query.get_hash

回答5:

You should be able to accomplish your goal easily with Mechanize.

Edit: Actually, if you already have the results, all you need is HPricot or Nokogiri.

回答6:

I don't know Ruby specific code but this google scraper could help you. That's an online tool demo that works scraping and parsing Google results. The most interesting thing is the article there with the explanation of the parsing process in PHP but it's applicable to Ruby and any other programming language.