code: def reverse(self):
          "reverse *IN PLACE*"
          leftblock = self.left
          rightblock = self.right
          leftindex = self.leftndx
          rightindex = self.rightndx
          for i in range(self.length // 2):
              # Validate that pointers haven't met in the middle
              assert leftblock != rightblock or leftindex < rightindex
  
              # Swap
              (rightblock[rightindex], leftblock[leftindex]) = (
                  leftblock[leftindex], rightblock[rightindex])
  
              # Advance left block/index pair
              leftindex += 1
              if leftindex == n:
                  leftblock = leftblock[RGTLNK]
                  assert leftblock is not None
                  leftindex = 0
  
              # Step backwards with the right block/index pair
              rightindex -= 1
              if rightindex == -1:
                  rightblock = rightblock[LFTLNK]
                  assert rightblock is not None
                  rightindex = n - f reverse(self):
          "reverse *IN PLACE*"
          leftblock = self.left
          rightblock = self.right
          leftindex = self.leftndx
          rightindex = self.rightndx
          for i in range(self.length // 2):
              # Validate that pointers haven't met in the middle
              assert leftblock != rightblock or leftindex < rightindex
  
              # Swap
              (rightblock[rightindex], leftblock[leftindex]) = (
                  leftblock[leftindex], rightblock[rightindex])
  
              # Advance left block/index pair
              leftindex += 1
              if leftindex == n:
                  leftblock = leftblock[RGTLNK]
                  assert leftblock is not None
                  leftindex = 0
  
              # Step backwards with the right block/index pair
              rightindex -= 1
              if rightindex == -1:
                  rightblock = rightblock[LFTLNK]
                  assert rightblock is not None
                  rightindex = n - 1
docs: reverse *IN PLACE*