code: def keys(self, desc = None):
          '''numpy asarray does not copy data'''
          res = asarray(self.rc('index'))
          if desc == True:
              return reversed(res)
          else:
              return ref keys(self, desc = None):
          '''numpy asarray does not copy data'''
          res = asarray(self.rc('index'))
          if desc == True:
              return reversed(res)
          else:
              return res
docs: numpy asarray does not copy data