title: Getting right elements from list in python
body: <p>I have a list, call it <code>test</code>, with 3 columns, each column has 891 elements, each element is a pair of floats.
  I want to create a numpy matrix with 3 columns, each of which has 891 elements, each element is the first entry from the pair of floats.</p>
  
  <p>I have the following code:</p>
  
  <pre><code>x = []
  y = []
  for i in range(len(test)):
      for j in range(len(test[0])):
          y.append(test[i][j][0])
      x.append(y)
      y = []
  
  tt = numpy.matrix(x) 
  </code></pre>
  
  <p>This works, but can I write it in a more efficient and elegant way?</p>
  
  <p>EDIT:
  Example:</p>
  
  <pre><code>[0.5, 0.5],[0.3, 0.4],[0.1, 0.4]
  [0.7, 0.6],[0.1, 0.4],[0.2, 0.3]
  [0.2, 0.5],[0.6, 0.9],[0.3, 0.2]
  [0.2, 0.5],[0.6, 0.9],[0.4, 0.1]
  </code></pre>
  
  <p>I want:</p>
  
  <pre><code>[0.5, 0.3, 0.1]
  [0.7, 0.1, 0.2]
  [0.2, 0.6, 0.3]
  [0.2, 0.6, 0.4]
  </code></pre>