code: def fetch_pi_file(filename):
      """This will download a segment of pi from super-computing.org
      if the file is not already present.
      """
  
      ftpdir = "ftp://pi.super-computing.org/.2/pi200m/"
      if os.path.exists(filename):
          # we already have it
          return
      else:
          # download it
          urlretrieve(ftpdir + filename, filename)
  
file_path: ipyparallel/examples/pi/pidigits.py
imports: import os
  from urllib.request import urlretrieve
  import numpy
  from matplotlib import pyplot
label_desc: Use image node_id 1 for calling a global function with example usage: fetch_pi_file(filename) without return types