## mark a section (Learn more)

require 'rubygems' require 'faster_csv' category_totals = {} FCSV.foreach('orig.csv') do |row| category_totals[row[0]] ||= 0 category_totals[row[0]] += row[1] end FCSV.open('output.csv','w') do |out| category_totals.each do |category,total| out << [category,total] end end

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