 <p>If I understand your desired output correctly, you can use <a href="https://docs.scipy.org/doc/numpy/reference/generated/numpy.reshape.html" rel="nofollow noreferrer"><code>numpy.reshape</code></a></p> <pre><code>&gt;&gt;&gt; spp = np.asarray(splist, dt) &gt;&gt;&gt; spp array([(2002, 10.502535211267606), (2003, 10.214794520547946), (2004, 9.811578947368423), (2015, 9.093658536585366), (2016, 9.244272537935139)], dtype=[('f0', '&lt;i4'), ('f1', '&lt;f8')]) &gt;&gt;&gt; np.reshape(spp, (spp.size, 1)) array([[(2002, 10.502535211267606)], [(2003, 10.214794520547946)], [(2004, 9.811578947368423)], [(2015, 9.093658536585366)], [(2016, 9.244272537935139)]], dtype=[('f0', '&lt;i4'), ('f1', '&lt;f8')]) </code></pre>