new_contents: # coding=utf-8
  '''
  Created on 10/3/2017 2:19 07PM Wang Weimin
  
  @author: wangwm
  '''
  
  import numpy as np
  import sys
  
  laser_beam_num=64
  def convert_arr_2_colored_pcd(xyzrgb_arr, save_path):
      rgb_pcd_header = ["# .PCD v.7 - Point Cloud Data file format", "VERSION .7", "FIELDS x y z rgb", "SIZE 4 4 4 4",
                        "TYPE F F F U", "COUNT 1 1 1 1"]
      all_points_num = len(xyzrgb_arr)
      print "all_points_num", all_points_num
      rgb_pcd_header.append("WIDTH " + str(all_points_num))
      rgb_pcd_header.append("HEIGHT 1")
      rgb_pcd_header.append("VIEWPOINT 0 0 0 1 0 0 0")
      rgb_pcd_header.append("POINTS " + str(all_points_num))
      rgb_pcd_header.append("DATA ascii")
  
      # save_path = "new_xyzrgb.pcd"
      f = open(save_path, "w")
      for line in rgb_pcd_header:
          f.write(line + "\n")
      for line in xyzrgb_arr:
          # color = np.array([0, 255, 0])
          # rgb_value = color[2] << 16 | color[1s] << 8 | color[0]
  
          color = line[3:].astype(np.uint32)
          rgb_value = color[0] << 16 | color[1] << 8 | color[2]
          f.write('{0:.4f}'.format(line[0]) + " " + '{0:.4f}'.format(line[1]) + " " + '{0:.4f}'.format(
              line[2]) + " " + str(rgb_value) + "\n")
      f.close()
      print "converted"
  
  
  csv_file = sys.argv[1]
  save_path = sys.argv[2]
  arr = np.genfromtxt(csv_file, skip_header=1, delimiter=",")[:, :5]
  
  new_arr_ls = []
  
  color_bar = np.random.randint(0, 255, [128, 3])
  
  for m in xrange(laser_beam_num):
      order = np.where(arr[:, 4] == m)  # the 4-th column means the laser id
      temp_data = arr[order[0]][:, :3]  # exact XYZ data with laser_id=i
      temp_point_num = temp_data.shape[0]
      for p in xrange(temp_point_num):
          color = np.array([int(float(p) / temp_point_num * 255), 0, 255 - int(float(p) / temp_point_num * 255)])
          # print color
          new_arr_ls.append(np.hstack([temp_data[p, :3], color]))
  
  convert_arr_2_colored_pcd(new_arr_ls, save_path)
  
subject: add folder for useful scripts