title: AttributeError: 'Graph' object has no attribute 'node'
body: <p>I have bellow python code to build knn graph but I have an error: AttributeError: 'Graph' object has no attribute 'node'. It seems that the nx.Graph() has no node attribute but I don't know what should I replace with that. </p>
  
  <pre><code>import networkx as nx
  def knn_graph(df, k, verbose=False):
      points = [p[1:] for p in df.itertuples()]
      g = nx.Graph()
      if verbose: print ("Building kNN graph (k = %d)" % (k))
      iterpoints = tqdm(enumerate(points), total=len(points)) if verbose else enumerate(points)
      for i, p in iterpoints:
          distances = map(lambda x: euclidean_distance(p, x), points)
          closests = np.argsort(distances)[1:k+1] # second trough kth closest
          for c in closests:
              g.add_edge(i, c, weight=distances[c])
          g.node[i]['pos'] = p
      return g
  </code></pre>