mecab.rb

require 'natto'
require 'csv'

if ARGV[0].nil?
  p "usage: ruby mecab.rb [filename]"
  exit
end

words_by_line = {}
CSV.open(ARGV[0], 'r') do |lines|
  mecab = Natto::MeCab.new
  lines.each_with_index do |line, index|
    words = []
    # 改行や句読点を削除
    body = line[1].gsub(/(\r\n|\r|\n|\f|、|。)/,"")
    mecab.parse(body) do |noun|
      words << noun.surface ? noun.surface : "-"
    end
    words_by_line[index] = words
  end
end

word_counts_by_line = {}
words_by_line.each_with_index do |line, index|
  word_count = []
  words_by_line[index].uniq.map do |word|
    word.gsub!(/(暴言１|暴言２)/, "ピー")
    word_count[word_count.size] = ["#{word}", "#{words_by_line[index].grep(word).count}"] if word
  end
  word_counts_by_line[index] = word_count
end

CSV.open('output.csv', 'wb') do |csv|
  word_counts_by_line.each_with_index do |line, index|
    csv << word_counts_by_line[index].sort_by { |word_and_count| word_and_count[1].to_i }.reverse
  end
end