text: import numpy as np
  # print(np.meshgrid(np.arange(100), np.arange(200)))
  frames=[]
  for i in range(10):
      frames.append([i,i,i,i])
  i0=frames[:2]
  i1=frames[2:]
  print(frames[:-1])
  print(frames[1:])
  ix = [i0, i1]
  print(ix)