code: def index2binary(index, npts=None):
      """convert a list of integers to a list of binary strings"""
      if npts is None:
          npts = max(index) + 1
      v = [binary(i) for i in index + [npts]]
      v = [((len(v[-1]) - len(i)) * "0" + i)[::-1] for i in v][:-1]
      return v
  
label_desc: Use image node_id 2 for calling a global function with example usage: index2binary(index, npts) and returns: v