code: def analyze(self, output_folder=".", auto_remove=False):
          
          if auto_remove:
              try:
                  shutil.rmtree(output_folder)
              except:
                  pass
          try:
              mkdir(output_folder)
          except:
              pass
          tokens = [token for sublist in self.sentences for token in sublist]
          df = pd.DataFrame(tokens)
          log = u""
          log += u"Sentences    : {}\n".format(len(self.sentences))
          n = df.shape[1]
          log += self._analyze_first_token(df, 0, output_folder)
          for i in range(1, n):
              log += self._analyze_field(df, i, output_folder)
          print(log)
          stat_file = join(output_folder, "stats.txt")
          write(stat_file, log)
docs: :type auto_remove: boolean
          :param boolean auto_remove: auto remove previous files in analyze folder