docs: def _process(self, input):
          '''
          Takes in html-mixed body text as a string and returns a list of strings,
          lower case and with punctuation given spacing. 
  
          Called by self._gen_sentence()
  
          Args:
              inpnut (string): body text
          '''
  
          input = re.sub("<[^>]*>", " ", input) 
          punct = list(string.punctuation)
          for symbol in punct:
              input = input.replace(symbol, " %s " % symbol)
          input = filter(lambda x: x != u'', input.lower().split(' '))
          return input