title: what is wrong with importing modules in scipy , is it a bug?
body: <p>ok , i don't think, i can explain this problem in words so , here is the snippet of ipython session , where i import scipy , in order to construct a sparse matrix.</p>
  
  <pre><code>In [1]: import scipy as sp
  
  In [2]: a = sp.sparse.lil_matrix((5,5))
          ---------------------------------------------------------------------------
          AttributeError                            Traceback (most recent call last)
         /home/liveuser/&lt;ipython-input-2-b5a55fc2d0ac&gt; in &lt;module&gt;()
          ----&gt; 1 a = sp.sparse.lil_matrix((5,5))
  
          AttributeError: 'module' object has no attribute 'sparse'
  
  In [3]: import scipy.sparse as spar
  
  In [4]: ax = spar.lil_matrix((5,5))
  
  In [5]: a = sp.sparse.lil_matrix((5,5)) # you are kidding me?
  
  In [6]: a
  Out[6]: 
         &lt;5x5 sparse matrix of type '&lt;type 'numpy.float64'&gt;'
         with 0 stored elements in LInked List format&gt;
  
  In [7]: ax
  Out[7]: 
         &lt;5x5 sparse matrix of type '&lt;type 'numpy.float64'&gt;'
         with 0 stored elements in LInked List format&gt;
  </code></pre>
  
  <p>what is happening there , why can't construct a sparse matrix using sp , in the first time , when i import sparse sub-module in a particular way (as in snippet) , both sp and spar variables can now be used to construct sparse matrices.(i guess they are just references to same object)</p>
  
  <p>I reproduced this python default shell , (so it is not ipython specific)</p>
  
  <p>what's going on , is it by design?? if so kindly elaborate. or is it a bug?? </p>
  
  <p>My system is Fedora 16 KDE-scientific,64 bit.</p>