input: Write a function to compress a given data sequence by grouping consecutive elements with the same sign or zero together. The function should return a list of lists where each sublist contains consecutive elements with the same sign or zero. If the input sequence is empty, return an empty list.
  def compress_sequence(nums):
      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
  
  assert compress_sequence([9, -2, 6, 0, -7]) == [[9], [-2], [6, 0], [-7]]
  assert compress_sequence([1, 2, 3, 4]) == [[1, 2, 3, 4]]
  assert compress_sequence([-1, -2, -3, -4]) == [[-1, -2, -3, -4]]
  assert compress_sequence([0, 0, 0, 0]) == [[0, 0, 0, 0]]
  assert compress_sequence([]) == []
output: def compress_sequence(nums):
      if not nums:
          return []
      output = []
      temp = [nums[0]]
  
      for i in range(1, len(nums)):
          if nums[i] * nums[i-1] >= 0:
              temp.append(nums[i])
          else:
              output.append(temp)
              temp = [nums[i]]
      output.append(temp)
  
      return output