title: NetworkX draw grid_2d_graph with nodelist value from file
body: <p>I am trying to draw grid_2d_graph with nodelist values from file.</p>
  
  <pre><code>list1 = [(0,0),(0,1),(1,0)] 
  nx.draw_networkx_nodes(G, pos, nodelist=list1, node_color='b')
  </code></pre>
  
  <p>In the above statement, instead of manually setting the nodelist, I want to read the nodelist from a file. That file will contain the list of nodes that should be colored blue. </p>
  
  <p>I tried reading from the file and putting the retrieved value in the nodelist, but its giving error Node '(0,1)' has no position because may be I am storing it as a string.  </p>
  
  <p>Can anyone please suggest how to read nodelist values from a file. </p>