code: def list2string(li, sep=","):
      return sep.join([str(a) for a in li])
  
file_path: recommenders/examples/07_tutorials/KDD2020-tutorial/utils/general.py
imports: import os
  import numpy
label_desc: Use image node_id 3 for calling a global function with example usage: list2string(li, sep) and returns: sep