title: Sparse arrays from tuples
body: <p>I searched the net to find a guide for Scipy sparse matrices and I failed. I would be happy if anybody would share any source for it but now going to question:</p>
  
  <p>I have an array of tuples. I want to change the array of tuples to a sparse matrix where the tuples appear on the main diagonal and diagonal just beside to it as the following example shows it. What is the fancy(efficient) way of doing it?</p>
  
  <pre><code>import numpy as np
  A=np.asarray([[1,2],[3,4],[5,6],[7,8]])
  B=np.zeros((A.shape[0],A.shape[0]+1))
  for i in range(A.shape[0]):
      B[i,i]=A[i,0]
      B[i,i+1]=A[i,1]
  print B
  </code></pre>
  
  <p>Output being:</p>
  
  <pre><code>[[ 1.  2.  0.  0.  0.]
   [ 0.  3.  4.  0.  0.]
   [ 0.  0.  5.  6.  0.]
   [ 0.  0.  0.  7.  8.]]
  </code></pre>