Ruby哈希值按多个值分组

Question

我有多个看起来像这样的哈希：

[{"name" => "name1", "folder" => "folder1", id => 1 },

{"name" => "name1", "folder" => "folder1", id => 2 },

{"name" => "name1", "folder" => "folder2", id => 3},

{"name" => "name2", "folder" => "folder1", id => 4}]

我的目标是拥有一个看起来像这样的东西：

   {"name1" => 
    [{"folder1" =>
      [{"name" => "name1", "folder" => "folder1", id => 1 },
       {"name" => "name1", "folder" => "folder1", id => 2 }] }
     {"folder2" => 
       [{"name" => "name1", "folder" => "folder2", id => 3}] }]

    {"name2" => 
     [{"folder 1" => 
       [{"name" => "name2", "folder" => "folder1", id => 4}] }] }

我暂时找不到能给出这种结果或类似结果的合适解决方案。

编辑：我尝试了很多其他方法，但是从未找到过使用两个层次的深层散列的方法a.group_by{|line| line["name"]}.each_value {|v| v.map{|line| line["folder"]}} a.group_by{|line| line["name"]}.each_value {|v| v.map{|line| line["folder"]}}

Answer 1

这似乎可以满足您的要求 ：

transformed_hash = initial_hash
  .group_by { |x| x['name'] }
  .map { |k, v| [k, v.group_by{ |x| x['folder'] }] }
  .to_h

Answer 2

a = [{"name" => "name1", "folder" => "folder1", 'id' => 1 },
{"name" => "name1", "folder" => "folder1", 'id' => 2 },
{"name" => "name1", "folder" => "folder2", 'id' => 3},
{"name" => "name2", "folder" => "folder1", 'id' => 4}]

a.group_by { |c| c['name'] }.map do |key, value| 
   [key, [value.group_by { |c| c['folder']}]]
end.to_h

 => {"name1"=>
       [{"folder1"=>[
          {"name"=>"name1", "folder"=>"folder1", "id"=>1},
          {"name"=>"name1", "folder"=>"folder1", "id"=>2}],   
         "folder2"=>[
          {"name"=>"name1", "folder"=>"folder2", "id"=>3}]}],    
     "name2"=>
       [{"folder1"=>[
          {"name"=>"name2", "folder"=>"folder1", "id"=>4}]}]
     }