title: Python Progam to read SDF (chemistry) file
body: <p>I want to read <a href="http://en.wikipedia.org/wiki/Chemical_table_file#SDF" rel="nofollow">sdf</a> file (containing many molecules) and return the weighted adjacency matrix of the molecule. Atoms should be treated as vertices and bond as edges. If <em>i</em> and <em>j</em> vertex are connected by single, double, or triple bond then corresponding entries in the adjacency matrix should be 1,2, and 3 respectively. I need to further obtain a <em>distance vector</em> for each vertex which list the number of vertices at different distance.</p>
  
  <p>Are there any python package available to do this?</p>