如何group_by此哈希数组

Question

我已将CSV格式的数据从文件读取到以下数组中：

arr = [
["company", "location", "region", "service", "price", "duration", "disabled"], 
["Google", "Berlin", "EU", "Design with HTML/CSS", "120", "30", "false"], ["Google", "San Francisco", "US", "Design with HTML/CSS", "120", "30", "false"], 
["Google", "San Francisco", "US", "Restful API design", "1500", "120", "false"],
["IBM", "San Francisco", "US", "Design with HTML/CSS", "120", "30", "true"],
["Google<script>alert('hi')<script>", "Berlin", "EU", "Practical TDD", "300", "60", "false"],
["Œoogle", "San Francisco", "US", "Restful API design", "1500", "120", "false"],
["Apple", "Berlin", "EU", "Practical TDD", "300", "60", "true"],
["Apple", "London", "EU", "Advanced AngularJS", "1200", "180", "false"],
["Apple", "New York", "US", "Restful API design", "1500", "120", "false"]
]

我想导入数据库中。 基于以下提到的关联

# company.rb
  has_many :regions
  has_many :services

# region.rb
  has_many :branches
  belongs_to :company

# branch.rb
  belongs_to :region
  has_many :services

# service.rb
  belongs_to :company
  belongs_to :branch

可以使用下面提到的哈希值：（不确定。请提出一个好的设计方案）

{"Google" : [ 
  :name => "Google",
  :regions_attributes => {
    :name => "US", 
    :locations_attributes => {
      :name => "San Francisco"
    }
  },
  :services_attributes: [{
    :name => "Restful API design",
    ...
  },
  {
    :name => "Design with HTML/CSS",
    ...
  }]
]}

我对此的尝试：

companies = []
CSV.foreach(csv_file, headers: true) do |row|
  company = {}
  company[:name]   = row['company']
  company[:regions_attributes] = {}
  company[:regions_attributes][:name] = row['region']
  company[:regions_attributes][:branches_attributes] = {}
  company[:regions_attributes][:branches_attributes][:name] = row['location']
  company[:services_attributes] = {}
  company[:services_attributes][:name] = row['service']
  company[:services_attributes][:price] = row['price']
  company[:services_attributes][:duration] = row['duration']
  company[:services_attributes][:disabled] = row['disabled']
  companies << company
end

companies.uniq! { |c| c.values }
companies = companies.group_by { |c| c[:name] }

它按公司名称分组。

如上例所述，我想将一个地区中的服务分组，即美国旧金山有两个服务。

更新资料

基于Cary Swoveland的解决方案，我可以根据需求进行修改，但关联无法按我的想法工作。

companies = CSV.read(csv_file, headers: true).group_by {|csv| csv["company"]}
final = []
companies.transform_values do |arr1|
  company = Company.new(name: arr1.pluck("company").first.encode(Encoding.find('ASCII'), encoding_options))
  services = arr1.map do |c|
    { name: c['service'], price: c['price'], duration: c['duration'], disabled: c['disabled'] }
  end.uniq
  company.services.build(services)
  regions = arr1.group_by { |csv| csv["region"] }.transform_values do |arr2|
    branches = []
    branches << arr2.pluck('location').uniq.map { |location| { name: location, services_attributes: services } }
    { name: arr2.pluck('region').uniq.first, branches_attributes: branches.flatten }
  end
  company.regions.build(regions.values)
  final << company
end

Company.import(final, recursive: true) #activerecord-import gem

Answer 1

考虑更改哈希的结构，并使用下面的代码进行构造。 文件'tmp.csv'包含csv文件的前20行左右，其链接由OP给出。 我已经在最后包含了它的内容。

require 'csv'

CSV.read('tmp.csv', headers: true).group_by { |csv| csv["company"] }.
    transform_values do |arr1|
      arr1.group_by { |csv| csv["region"] }.
           transform_values do |arr2|
             arr2.group_by { |csv| csv["location"] }.
                  transform_values do |arr2|
                    arr2.map { |csv| csv["service"] }.uniq
                  end
           end
    end

  #=> {"Google"=>{
         "EU"=>{
           "Berlin"=>["Design with HTML/CSS","Advanced AngularJS","Restful API design"],
           "London"=>["Restful API design"]
         },
         "US"=>{
            "San Francisco"=>["Design with HTML/CSS", "Restful API design"]
         }
       },
       "Apple"=>{
         "EU"=>{
           "London"=>["Design with HTML/CSS"],
           "Berlin"=>["Restful API design"]
         },
         "US"=>{
           "San Francisco"=>["Design with HTML/CSS"]
         }
       },
       "IBM"=>{
         "US"=>{
           "San Francisco"=>["Design with HTML/CSS"]
         },
         "EU"=>{
           "Berlin"=>["Restful API design"],
           "London"=>["Restful API design"]
         }
      }
     }

如果此哈希格式不合适（但需要的是内容），则可以轻松将其更改为其他格式。

有关CSV :: read ， CSV :: Row＃[] ， Enumerable＃group_by和Hash＃transform_values的信息 ，请参见文档。

我被要求对链接的csv文件进行一些预处理。 问题是，公司名称的前面是UTF-8文件的“字节顺序标记”（ 在这里搜索“确定，确定了”。）我使用Nathan Long在此处指定的代码删除了这些字符。 OP将不得不写入没有这些标记的CSV文件，或者在读取文件时将其剥离。

The content of my reduced CSV test file is the following.

arr = ["company,location,region,service,price,duration,disabled\n",
       "Google,Berlin,EU,Design with HTML/CSS,120,30,FALSE\n",
       "Google,San Francisco,US,Design with HTML/CSS,120,30,FALSE\n",
       "Google,San Francisco,US,Restful API design,1500,120,FALSE\n",
       "Apple,London,EU,Design with HTML/CSS,120,30,FALSE\n",
       "Google,Berlin,EU,Design with HTML/CSS,120,30,FALSE\n",
       "Apple,Berlin,EU,Restful API design,1500,120,FALSE\n",
       "IBM,San Francisco,US,Design with HTML/CSS,120,30,TRUE\n",
       "Google,San Francisco,US,Design with HTML/CSS,120,30,FALSE\n",
       "IBM,Berlin,EU,Restful API design,1500,120,TRUE\n",
       "IBM,London,EU,Restful API design,1500,120,TRUE\n",
       "IBM,Berlin,EU,Restful API design,1500,120,TRUE\n",
       "IBM,London,EU,Restful API design,1500,120,TRUE\n",
       "IBM,San Francisco,US,Design with HTML/CSS,120,30,TRUE\n",
       "Google,Berlin,EU,Advanced AngularJS,1200,180,FALSE\n",
       "Google,Berlin,EU,Restful API design,1500,120,FALSE\n", 
       "Google,London,EU,Restful API design,1500,120,FALSE\n",
       "Apple,San Francisco,US,Design with HTML/CSS,120,30,FALSE\n",
       "Google,San Francisco,US,Restful API design,1500,120,FALSE\n",
       "IBM,Berlin,EU,Restful API design,1500,120,TRUE\n"]