title: Struggling with dynamics ndarray
body: <p>I am a MATLAB user.
  What is the easiest way to port the following MATLAB script to python</p>
  
  <pre><code>a = []
  for i=1:10
      for j=1:10
          a(i,j) =  i*j
      end
  end
  </code></pre>
  
  <p>The question is about dynamically use np.ndarrays. In MATLAB I can initialize a as generical ndarray(via a=[]) without knowing its size, then use the explicit indexing a(i,j).
  In Python there is the .append method, but when using ndarrays it confuses me, because it would require to pack element of a row first, then pack rows together, or something similar. I would prefer explicit indexing. Is this possible togheter with dynamical arrays or it can be done just with fixed size arrays?</p>
  
  <p>Thanks!</p>