yml_to_tsv.rb

require 'yaml'
require 'csv'

if ARGV.size == 2
  data = YAML.load_file(ARGV[0])
  CSV.open(ARGV[1], 'wb', col_sep: '\t') do |csv|
    csv << data.first.keys
    data.to_a.each { |item| csv << item.values }
  end
else
  STDERR.puts 'usage: ruby yml_to_tsv.rb path/to/yml path/to/tsv'
end