Array of hashes to CSV

hash_array_to_csv.rb

require 'csv'

def hash_array_to_csv(hash_arr, fname='csv.csv')
  headers = hash_arr.map{|hsh| hsh.keys}.flatten.uniq
  csv = CSV.generate do |csv|
    csv << headers
    hash_arr.each do |hsh|
      csv << (headers.map{|k| hsh[k]})
    end
  end
  File.write(fname, csv) if fname
  return csv
end