code: def _get_char(self):
          
  
          if self.ungotten_char is None:
              if self.eof:
                  c = ''
              else:
                  c = self.file.read(1)
                  if c == '':
                      self.eof = True
                  elif c == '\n':
                      self.line_number += 1
          else:
              c = self.ungotten_char
              self.ungotten_char = None
          return c
docs: Read a character from input.
          @rtype: string