code: def load_snp500():
      """
      Loads pandas dataframe of S&P 500 daily values from 1927-12-30 thru 2020-01-10.
      """
      _mkdir_p(DATA)
      filename = os.path.join(DATA, "snp500.csv.bz2")
      if not os.path.exists(filename):
          urllib.request.urlretrieve(CACHE_URL, filename)
      df = pd.read_csv(filename)
      return df
  
imports: import os
  import urllib
  import pandas
  from pyro.contrib.examples.util import _mkdir_p, get_data_directory
label_desc: Use image node_id 1 for calling a global function with example usage: load_snp500() and returns: df