code: def CheckForUpdate(source, target):
      '''
      Checks if the given target filename should be re-generated because the source has changed.
      :param source: the source filename.
      :param target: the target filename.
      :return bool:
          True if the target is out-dated, False otherwise.
      '''
      return \
          not os.path.isfile(target) or \
          os.path.getmtime(source) > os.path.getmtime(targetf CheckForUpdate(source, target):
      '''
      Checks if the given target filename should be re-generated because the source has changed.
      :param source: the source filename.
      :param target: the target filename.
      :return bool:
          True if the target is out-dated, False otherwise.
      '''
      return \
          not os.path.isfile(target) or \
          os.path.getmtime(source) > os.path.getmtime(target)
docs: Checks if the given target filename should be re-generated because the source has changed.
      :param source: the source filename.
      :param target: the target filename.
      :return bool:
          True if the target is out-dated, False otherwise.