関連ワード:  how to define null array in python    how to define blank array in python    how to initialize empty array in python    how to assign empty array in python    how to define empty 2d array in python    how to initialize empty 2d array in python    how to declare an empty array in python with size    how to initialize empty numpy array in python    how to initialize a blank array in python    how to define an empty numpy array in python