ruby code for validating rows in a csv file

validate_data.rb

valid = []
invalid = []
File.open('file.txt') do |f|
  f.each_line do |l|
     user_id, item_id, price_id = l.split(',').map {|x| x.strip.to_i}
     if user_id.to_s.size == 5 && item_id.to_s.size >= 1 && item_id.to_s.size <= 3 && price_id     > 0
         valid << l
     else
         invalid << l
     end
  end
end

File.open('valid.txt', 'w') {|f| f.puts(valid)}
File.open('invalid.txt', 'w') {|f| f.puts(invalid)}