code: def download_and_extract(download_to, extract_to):
      url = "http://phontron.com/data/ted_talks.tar.gz"
      filename = f"{download_to}/ted_talks.tar.gz"
      if os.path.exists(filename):
          print(f"{filename} has already been downloaded so skip")
      else:
          filename = wget.download(url, filename, bar=bar_custom)
      if os.path.exists(f"{extract_to}/all_talks_train.tsv"):
          print(f"Already extracted so skip")
      else:
          extract_cmd = f'tar xzfv "{filename}" -C "{extract_to}"'
          call(extract_cmd)
  
imports: import itertools
  import os
  import csv
  from collections import defaultdict
  from six.moves import zip
  import io
  import wget
  import sys
  from subprocess import check_call, check_output
label_desc: Use image node_id 8 for calling a global function with example usage: download_and_extract(download_to, extract_to) without return types