yoshiyoshifujii https://blog.hatena.ne.jp/yoshiyoshifujii/ 毎日Learning https://yoshiyoshifujii.hatenablog.com/ Python L-99 def dupli(lista): return reduce(lambda x,y: x+[y,y], lista, []) if isinstance(lista, list) else None if __name__ == "__main__": print dupli("a") == None print dupli([]) == [] print dupli(["a"]) == ["a", "a"] print dupli(["a", "b"]) == ["a", "a", "b", "b"] print dupli(["a", "b", "c"]) == ["a", "a", "… 190 <iframe src="https://hatenablog-parts.com/embed?url=https%3A%2F%2Fyoshiyoshifujii.hatenablog.com%2Fentry%2F20100728%2Fp3" title="P14 (*) リストの各要素を2連続させる。 - 毎日Learning" class="embed-card embed-blogcard" scrolling="no" frameborder="0" style="display: block; width: 100%; height: 190px; max-width: 500px; margin: 10px 0px;"></iframe> Hatena Blog https://hatena.blog 2010-07-28 00:00:02 rich https://yoshiyoshifujii.hatenablog.com/entry/20100728/p3 1.0 100%