input: def compress_sequence(nums):
      """Compress a given data sequence by grouping consecutive numbers with the same sign.
      >>> compress_sequence([9, -2, 6, 0, -7])
      [[9], [-2], [6, 0], [-7]]
      """
      output = []
      temp = []
  
      for i in range(1, len(nums)):
          if nums[i-1] * nums[i] >= 0:
              temp.append(nums[i-1])
          else:
              temp.append(nums[i-1])
              output.append(temp)
              temp = []
      temp.append(nums[i])
      output.append(temp)
  
      return output
output:     output = []
      temp = [nums[0]]
  
      for i in range(1, len(nums)):
          if (nums[i-1] >= 0 and nums[i] >= 0) or (nums[i-1] < 0 and nums[i] < 0):
              temp.append(nums[i])
          else:
              output.append(temp)
              temp = [nums[i]]
      output.append(temp)
  
      return output