The extension method from String class for ruby. The objective of the method is for the text analysis preprocessing removing the irrevelevant words (especially Twitter feature).

twitterfeature_remover.rb

class String

  def remove_reply(remain_username = false)
    if remain_username
      self.gsub(/[@]{1}/,"")
    else
      self.gsub(/[@]{1}[\w]{1,}/,"")
    end
  end

  def remove_emoji()
    emoji = /[\u{00A9}\u{00AE}\u{203C}\u{2049}\u{2122}\u{2139}\u{2194}-\u{2199}\u{21A9}-\u{21AA}\u{231A}-\u{231B}\u{2328}\u{23CF}\u{23E9}-\u{23F3}\u{23F8}-\u{23FA}\u{24C2}\u{25AA}-\u{25AB}\u{25B6}\u{25C0}\u{25FB}-\u{25FE}\u{2600}-\u{2604}\u{260E}\u{2611}\u{2614}-\u{2615}\u{2618}\u{261D}\u{2620}\u{2622}-\u{2623}\u{2626}\u{262A}\u{262E}-\u{262F}\u{2638}-\u{263A}\u{2648}-\u{2653}\u{2660}\u{2663}\u{2665}-\u{2666}\u{2668}\u{267B}\u{267F}\u{2692}-\u{2694}\u{2696}-\u{2697}\u{2699}\u{269B}-\u{269C}\u{26A0}-\u{26A1}\u{26AA}-\u{26AB}\u{26B0}-\u{26B1}\u{26BD}-\u{26BE}\u{26C4}-\u{26C5}\u{26C8}\u{26CE}-\u{26CF}\u{26D1}\u{26D3}-\u{26D4}\u{26E9}-\u{26EA}\u{26F0}-\u{26F5}\u{26F7}-\u{26FA}\u{26FD}\u{2702}\u{2705}\u{2708}-\u{270D}\u{270F}\u{2712}\u{2714}\u{2716}\u{271D}\u{2721}\u{2728}\u{2733}-\u{2734}\u{2744}\u{2747}\u{274C}\u{274E}\u{2753}-\u{2755}\u{2757}\u{2763}-\u{2764}\u{2795}-\u{2797}\u{27A1}\u{27B0}\u{27BF}\u{2934}-\u{2935}\u{2B05}-\u{2B07}\u{2B1B}-\u{2B1C}\u{2B50}\u{2B55}\u{3030}\u{303D}\u{3297}\u{3299}\u{1F004}\u{1F0CF}\u{1F170}-\u{1F171}\u{1F17E}-\u{1F17F}\u{1F18E}\u{1F191}-\u{1F19A}\u{1F201}-\u{1F202}\u{1F21A}\u{1F22F}\u{1F232}-\u{1F23A}\u{1F250}-\u{1F251}\u{1F300}-\u{1F321}\u{1F324}-\u{1F393}\u{1F396}-\u{1F397}\u{1F399}-\u{1F39B}\u{1F39E}-\u{1F3F0}\u{1F3F3}-\u{1F3F5}\u{1F3F7}-\u{1F4FD}\u{1F4FF}-\u{1F53D}\u{1F549}-\u{1F54E}\u{1F550}-\u{1F567}\u{1F56F}-\u{1F570}\u{1F573}-\u{1F579}\u{1F587}\u{1F58A}-\u{1F58D}\u{1F590}\u{1F595}-\u{1F596}\u{1F5A5}\u{1F5A8}\u{1F5B1}-\u{1F5B2}\u{1F5BC}\u{1F5C2}-\u{1F5C4}\u{1F5D1}-\u{1F5D3}\u{1F5DC}-\u{1F5DE}\u{1F5E1}\u{1F5E3}\u{1F5EF}\u{1F5F3}\u{1F5FA}-\u{1F64F}\u{1F680}-\u{1F6C5}\u{1F6CB}-\u{1F6D0}\u{1F6E0}-\u{1F6E5}\u{1F6E9}\u{1F6EB}-\u{1F6EC}\u{1F6F0}\u{1F6F3}\u{1F910}-\u{1F918}\u{1F980}-\u{1F984}\u{1F9C0}]/
    self.gsub(emoji, "")
        .gsub("amp;","")
  end

  def remove_retweet()
    self.gsub(/(RT|rt|via)/,"")
  end

  def remove_hashtag(remain_word = false)
    if remain_word
      self.gsub(/[#]{1}/,"")
    else
      self.gsub(/[#]{1}\w{1,}/,"")
    end
  end

  def repair_quote()
    self.gsub(/('s|’s)/,"")
        .gsub(/(”|“)/,"\"")
        .gsub(/(’|‘)/,"'")
  end

  def remove_url()
    self.gsub(/[h]{1}[t]{2}[p]{1}[s]{0,1}[\:]{0,1}[\/]{2}[\S\d\w\.]{1,}/,"") #remove simple url
  end

  def remove_symbol()
    self.gsub(/[…:!@#%$&?*+,=\|\”\‘\-\`\~\"\(\)\[\]\{\}\<\>\,\\\/\^]/," ")
        .gsub(/[^\.\w\s]/," ")
  end

  def remove_newline()
    self.gsub(/[\n]{1,}/," ")
  end

  def remove_twitter_feature(remain_hashtag = true, remain_username = true)
    self.remove_hashtag(remain_hashtag)
        .remove_reply(remain_username)
        .remove_retweet()
  end
end