title: Accessing every second row in matrix and save it to a new matrix, Python
body: <p>I am new to python and struggling with the following problem.</p>
  
  <p>I have a Matrix (6x2) and I want to save every second row into a new Matrix (3x2).</p>
  
  <pre><code>M = numpy.array([[1,2],[3,4],[5,6],[7,8],[9,10],[11,12]])
  SM = []
  for i in M(0,len(M),2):
    append.SM(i)
  </code></pre>
  
  <p>Is that even possible? Or do I have to split every single column first?
  SM should then look like that:</p>
  
  <pre><code>SM = [[3,4],[7,8],[11,12]]
  </code></pre>
  
  <p>So far, I only found how to do that with a single column vector, that doesn't help, as I am not used to Python at all. 
  Thanks in advance for you help.</p>