Question

我正在使用网络抓取工具从网站上删除以下数据。

组
分类
搜索属性

我使用以下代码将数据保存到三个单独的（单维）JSON文件中：

require 'mechanize'

@raw_groups_array = []
@raw_categories_array = []
@search_attributes = []

@groups_clean = []
@categories_clean = []

@categories_combined = []

@categories_hash = {}

# Initialize Mechanize object
a = Mechanize.new

# Begin magic
a.get('http://www.marktplaats.nl/') do |page|
  groups = page.search('//*[(@id = "navigation-categories")]//a')
  groups.each do |group|
    @raw_groups_array.push(group)
    @groups_clean.push(group.text)

    a.get(group[:href]) do |page_2|
      categories = page_2.search('//*[(@id = "category-browser")]//a')
      categories.each do |category|
        @raw_categories_array.push(category)
        @categories_clean.push(category.text)
        @categories_combined.push("#{group.text} | #{category.text}")

        a.get(category[:href]) do |page_3|
          search_attributes = page_3.search('//*[contains(concat( " ", @class, " " ), concat( " ", "heading", " " ))]')

          search_attributes.each do |attribute|
            @search_attributes.push("#{group.text} | #{category.text} | #{attribute.text}") unless attribute.text == 'Outlet '

            # Uncomment the line below if you want to see what's going on.
            # (it has minimal effect on performance)
            puts "#{group.text} | #{category.text} | #{attribute.text}" unless attribute.text == 'Outlet '
          end
        end
      end
    end
  end
end

# Write json files
File.open('json/prestige/prestige_groups.json', 'w') do |f|
  puts '# Writing groups'
  f.write(@groups_clean.to_json)
  puts '|-----------> Done.'
end

File.open('json/prestige/prestige_categories.json', 'w') do |f|
  puts '# Writing categories'
  f.write(@categories_clean.to_json)
  puts '|-----------> Done.'
end

File.open('json/prestige/prestige_combined.json', 'w') do |f|
  puts '# Writing combined'
  f.write(@categories_combined.to_json)
  puts '|-----------> Done.'
end

File.open('json/prestige/prestige_search_attributes.json', 'w') do |f|
  puts '# Writing search attributes'
  f.write(@search_attributes.to_json)
  puts '|-----------> Done.'
end

puts '# Finished.'

代码有效。但我很难重构它以下列格式创建一个红宝石哈希：

{
  "category"=>{
    "name"=>"#{category}",
    "group"=>"#{group}",
    "search_attributes"=>{
      "1"=>"#{search_attributes[0]}",
      "2"=>"#{search_attributes[1]}",
      "."=>"#{search_attributes[.]}",
      "i"=>"#{search_attributes[i]}", # depending on search_attributes.length
    }
  }
}

我尝试过这样的事情：

...
search_attributes.each do |attribute|
  @categories_hash.store([:category][:name], category.text)
  @categories_hash.store([:category][:group], group.text)
  @categories_hash.store([:category][:search_attributes][:1], attribute.text)
end
...

但不断收到语法错误。

任何帮助都将不胜感激。

更新

Max建议我尝试Hash#[]，但这会返回一个包含单个类别（最后一个）的哈希。

search_attributes.each_with_index do |attribute, index|
  @categories_hash[:category][:name] = category.text
  @categories_hash[:category][:group] = group.text
  @categories_hash[:category][:search_attributes][:"#{index}"] = attribute.text unless attribute.text == "Outlet "   
end

我已粘贴完整代码here。

Answer 1

您是否有使用Hash#store的特殊原因？这种方法没有简单的方法。

我认为使用Hash#[]会更好。

@categories_hash[:category] ||= {}
@categories_hash[:category][:search_attributes] ||= {}
@categories_hash[:category][:search_attributes][:1] = attribute.text

||=确保在您尝试在其中存储内容之前初始化subhash。

Answer 2

在here，here和here的帮助下，我有完整的代码：

require 'mechanize'

@hashes = []

# Initialize Mechanize object
a = Mechanize.new

# Begin scraping
a.get('http://www.marktplaats.nl/') do |page|
  groups = page.search('//*[(@id = "navigation-categories")]//a')
  groups.each_with_index do |group, index_1|

    a.get(group[:href]) do |page_2|
      categories = page_2.search('//*[(@id = "category-browser")]//a')
      categories.each_with_index do |category, index_2|

        a.get(category[:href]) do |page_3|
          search_attributes = page_3.search('//*[contains(concat( " ", @class, " " ), concat( " ", "heading", " " ))]')

          attributes_hash = {}

          search_attributes.each_with_index do |attribute, index_3|
            attributes_hash[index_3.to_s] = "#{attribute.text unless attribute.text == 'Outlet '}"
          end

          item = {
            id: "#{index_1}.#{index_2}",
            name: category.text,
            group: group.text,
            :search_attributes => attributes_hash
          }

          @hashes << item

          # Uncomment this if you want to see what's being pushed
          puts item
        end
      end
    end
  end
end

# Open file and begin
File.open("json/light/#{Time.now.strftime '%Y%m%d%H%M%S'}_light_categories.json", 'w') do |f|
  puts '# Writing category data to JSON file'
  f.write(@hashes.to_json)
  puts "|-----------> Done. #{@hashes.length} written."
end

puts '# Finished.'

如何将数据保存到多维Ruby哈希，然后将哈希转换为单个JSON文件？

2 个答案: