code: def get_date_postfix():
      """Get a date based postfix for directory name.
      Returns
      -------
      post_fix : str
      """
      dt = datetime.datetime.now()
      post_fix = "{}_{:02d}-{:02d}-{:02d}".format(
          dt.date(), dt.hour, dt.minute, dt.second
      )
  
      return post_fix
  
imports: import datetime
  import errno
  import os
  import pickle
  import random
  from pprint import pprint
  import dgl
  import numpy
  import torch
  from dgl.data.utils import _get_dgl_url, download, get_download_dir
  from scipy import io, sparse
label_desc: Use image node_id 3 for calling a global function with example usage: get_date_postfix() and returns: post_fix