title: Python: read adjacency matrix from file with networkx
body: <p>I try to read adjacency matrix from file with .dat extension, where data looks like</p>
  
  <pre><code>0   1   1   1   1   1
  1   0   1   1   1   1
  1   1   0   1   1   1
  1   1   1   0   1   1
  1   1   1   1   0   1
  1   1   1   1   1   0
  </code></pre>
  
  <p>(it's only part of file, there are 128 strings).
  I use <code>networkx</code> to read file and to do next operations, but after reading I use</p>
  
  <pre><code>g = nx.read_adjlist("adjacency_matrix/Cont_matr-1.dat")
  print(g.number_of_nodes())
  </code></pre>
  
  <p>I get <code>2</code>.
  But this number more than <code>2</code>.
  Maybe it's wrong way of reading file?</p>