docs: def do_cd(self, path = '/'):
          """change current working directory"""
          path = path[0]
  
          if path == "..":
              self.current_path = "/".join(self.current_path[:-1].split("/")[0:-1]) + '/'
          elif path == '/':
              self.current_path = "/"
          else:
              if path[-1] == '/':
                  self.current_path += path
              else:
                  self.current_path += path + '/'
  
          resp = self.n.getList(self.current_path, type=3)
  
          if resp:
              self.dirs = []
              self.files = []
  
              for f in resp:
                  name = f['href'].encode('utf-8')
  
                  if name[-1] == '/':
                      self.dirs.append(os.path.basename(name[:-1]))
                  else:
                      self.files.append(os.path.basename(name))
  
          self.prompt = "> %s@Ndrive:%s " %(self.id, self.current_path)