Convert ranges from old format to new

convert_range.rb

# convert from 
# (0 - 21 - 71 - 121) : (0 - 0,491 - 0,563 - 0,66)
# to
# (0-20:0); (21-70:0.491); (71-120:0.563); (121:0.66)
require 'csv'

module ConvertRange
  def self.convert(str)
    ranges, values = str.split(":")
    ranges.gsub!(/[^\d-]/, '')
    values.gsub!(/[\s\(\)]/, '')

    arr = ranges.split("-").map(&:to_i)
    arr = arr.each_with_index.map { |val, i| [val, arr[i + 1].to_i - 1] }
    lst = arr.pop
    arr = arr.map { |a, b| "#{a}-#{b}" }
    arr << "#{ lst.first }"

    arr.zip(values.gsub(/,/, '.').split("-")).map { |a, b| "(#{a}:#{b})"}.join("; ")
  end
end

["cessa", "lpz", "cre", "elfec", "endebeni", "elfeo", "sepsa", "setar"].each do |file|
  path = "/home/boris/Desktop/#{ file }.csv"
  next  unless File.exists?(path)
  puts "converting #{file}"
  arr = CSV.read(path)
  str = CSV.generate do |csv|
    arr.each do |row|
      [11, 12, 13, 14].each do |pos|
        row[pos] = ConvertRange.convert(row[pos])  if !row[pos].nil? && row[pos].strip != ""
      end
      csv << row
    end
  end

  f = File.new("/home/boris/Desktop/#{ file }_mod.csv", "w+")
  f.write(str)
end