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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _download_and_clean_file(filename, url):
 """Downloads data from url, and makes changes to match the CSV format."""

  temp_file, _ = urllib.request.urlretrieve(url)
  with tf.gfile.Open(temp_file, 'r') as temp_eval_file:
    with tf.gfile.Open(filename, 'w') as eval_file:
      for line in temp_eval_file:
        line = line.strip()
        line = line.replace(', ', ',')
        if not line or ',' not in line:
          continue
        if line[-1] == '.':
          line = line[:-1]
        line += '\n'
        eval_file.write(line)
  tf.gfile.Remove(temp_file)