code: def crop(im, r, c, sz_h, sz_w):
      '''
      crop image into a square of size sz,
      '''
      return im[r:r+sz_h, c:c+sz_wf crop(im, r, c, sz_h, sz_w):
      '''
      crop image into a square of size sz,
      '''
      return im[r:r+sz_h, c:c+sz_w]
docs: crop image into a square of size sz,