code: def atomic_write(filename, filesync=False):
    
  
    tmpf = tempfile.NamedTemporaryFile(delete=False)
    try:
      with open(tmpf.name, 'w') as curfile:
        yield curfile
        if filesync:
          curfile.flush()
          os.fsync(curfile.fileno())
      os.rename(tmpf.name, filename)
    finally:
      try:
        os.remove(tmpf.name)
      except (IOError, OSError):
        pass
docs: atomically write a file (using a temporary file).
  
    filename: the file to be written
    filesync: flush the file to disk