Posti postcode fetch and parse

gistfile1.txt

class PostcodesRequest
  require 'open-uri'
  require 'nokogiri'

  def postcode_file_name
    page   = Nokogiri::HTML(open('http://www.posti.fi/webpcode/unzip/'))
    href   = page.css('p').css('a')
    text   = href.text
    splits = text.split('webpcode/')
    names  = splits[1].split('.dat')
    "#{names.detect { |name| name =~ /PCF/ }}.dat"
  end

  def dat_file_split_by_lines
    url = "http://www.posti.fi/webpcode/unzip/#{postcode_file_name}"
    URI.open(url, 'r:ISO-8859-1:UTF-8') do |io|
      io.read.each_line
    end
  end

  def fetch_and_insert_into_db
    dat_file_split_by_lines.each do |row|
      args = { postcode:    row[13, 5],
               city_fi:     row[18, 30].strip.capitalize,
               city_sv:     row[48, 30].strip.capitalize,
               province_fi: row[116, 30].strip,
               province_sv: row[146, 30].strip,
               town_fi:     row[179, 20].strip,
               town_sv:     row[199, 20].strip }
      Postcode.update(args)
    end
  end
end