CODEWITHSUNDEEP
rubyjsoncsvruby-on-rails-4hash
Longshanks
Longshanks

Reputation: 97

Merging multiple data files into a single output then creating a file from this

Morning,

I am trying to create a function within rails to merge 3 files, I have 2 CSV files and 1 JSON file, These files all relate to books, The 3 files have different parts of data for the same books, so one CSV has a title and ID, the other has a different title with the same ID and a DOI, The JSON file has a hash with the authors name as the key and the value is an array of all the DOIs for the books.

Example data:

CSV One:

DOI,Title,ID
1111,Ruby on Rails,1234-1234
2222,Rails 4.0,4321-4321

CSV Two:

Title,ID
Ruby,1234-1234
Rails,4321-4321

JSON:

[{"name":"Homer Simpson","articles":["1111","2222"]}]

Example output (as JSON),

    [{
    "doi": "1111",
    "title": "Ruby on Rails",
    "author": "Homer Simpson",
    "book": "Ruby",
    "ID": "1234-1234"
    }
    {
    "doi": "2222",
    "title": "Rails 4.0",
    "author": "Homer Simpson",
    "book": "Rails",
    "ID": "4321-4321"
    }]

I know I need to parse the data initially, convert the CSV to array and then iterate through them, the bit i'm struggling with is the merging into a single hash.

Upvotes: 2

Views: 990

Answers (1)

Sayuj
Sayuj

Reputation: 7612

require 'csv'
require 'json'

csv1 = CSV.open('csv1.csv').read
csv2 = CSV.open('csv2.csv').read
csv1.shift
csv2.shift
@json = JSON.parse('[{"name":"Homer Simpson","articles":["1111","2222"]}]')

@csv1_data = csv1.inject([]) do |res, el|
  res << { doi: el[0], title: el[1], id: el[2] }
  res
end

@csv2_data = csv2.inject([]) do |res, el|
  res << { book: el[0], id: el[1] }
  res
end

def book_attributes(id)
  @csv2_data.find { |el| el[:id] == id }
end

def author_attributes(doi)
  item = @json.find { |el| el['articles'].include? doi }
  { author: item['name'] }
end


result = @csv1_data.inject([]) do |res, el|
  details = el.merge(author_attributes(el[:doi]))
  details.merge!(book_attributes(el[:id]))
  res << details
  res
end

puts result

Hope this will do.

Upvotes: 1

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