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    <h2>A question for your question</h2> <p>While Sven and Navi have answered your question on how to convert </p> <pre><code>x = scipy.matrix([1,2,3]).transpose() </code></pre> <p>into a list, I'll ask a question before answering:</p> <ul> <li>Why are you using an Nx1 matrix instead of an array?</li> </ul> <h2>Using array instead of matrix</h2> <p>If you look at the Numpy for Matlab Users wiki/documentation page, section 3 discusses <a href="http://www.scipy.org/NumPy_for_Matlab_Users#head-e9a492daa18afcd86e84e07cd2824a9b1b651935" rel="nofollow"><em>'array' or 'matrix'? Which should I use?</em></a>. The short answer is that you should use array.</p> <p>One of the advantages of using an array is that:</p> <blockquote> <p>You can treat rank-1 arrays as either row or column vectors. dot(A,v) treats v as a column vector, while dot(v,A) treats v as a row vector. This can save you having to type a lot of transposes.</p> </blockquote> <p>Also, as stated in the <a href="http://docs.scipy.org/doc/numpy/reference/arrays.classes.html#matrix-objects" rel="nofollow">Numpy Reference Documentation</a>, "Matrix objects are always two-dimensional." This is why <code>x.tolist()</code> returned a nested list of <code>[[1], [2], [3]]</code> for you.</p> <p>Since you want an Nx1 object, I'd recommend using array as follows:</p> <pre><code>&gt;&gt;&gt; import scipy &gt;&gt;&gt; x = scipy.array([1,2,3]) &gt;&gt;&gt; x array([1, 2, 3]) &gt;&gt;&gt; y = x.tolist() // That's it. A clean, succinct conversion to a list. &gt;&gt;&gt; y [1, 2, 3] </code></pre> <h2>If you really want to use matrix</h2> <p>If for some reason you truly need/want to use a matrix instead of an array, here's what I would do:</p> <pre><code>&gt;&gt;&gt; import scipy &gt;&gt;&gt; x = scipy.matrix([1,2,3]).transpose() &gt;&gt;&gt; x matrix([[1], [2], [3]]) &gt;&gt;&gt; y = x.T.tolist()[0] &gt;&gt;&gt; y [1, 2, 3] </code></pre> <p>In words, the <code>x.T.tolist()[0]</code> will:</p> <ol> <li>Transpose the x matrix using the <code>.T</code> attribute</li> <li>Convert the transposed matrix into a nested list using <code>.tolist()</code></li> <li>Grab the first element of the nested listed using <code>[0]</code></li> </ol>
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    1. COOK thanks, I see what you're saying - it does make it a lot cleaner to use an array instead. To answer your question: I chose matrix over array because I want to do some simple linear algebra, and I thought it would be easier to work with types that are less generalised. In particular, the * operator does proper matrix multiplication instead of elementwise multiplication (I know I can use multiply(), but I thought it would've been more convenient)
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    2. COUsing matrix for linear algebra is more convenient, since A*B is matrix multiplication.
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