count_profanity.rb

require 'csv'

tweets = CSV.read('tweets.csv')
tweets.shift

stats = tweets
  .reject { |t| t[5] =~ /^RT/ }
  .group_by { |t|
    date = Date.parse t[3]
    "#{date.year}-#{date.month}"
  }
  .map { |month, tweets|
    swearing = tweets
      .map    { |t| t[5] }
      .reject { |t| t =~ /^RT/ }
      .select { |t| t=~/(fuck|shit|crap| ass )/i }
    
    [month, tweets.count, swearing.count, (swearing.count.to_f / tweets.count.to_f).round(3).to_s.sub('.', ',')]
  }
  .reverse

# p stats

stats.unshift %w(Date All Swearing %)
IO.write 'stats.csv', stats.map { |row| row.join(';') }.join("\n") # to_csv doesn't work with Numbers.app