title: Python Reading from a file to create a weighted directed graph using networkx
body: <p>I am new at python and Spyder.
  I am trying to read from a text file with format into a graph using networkx:</p>
  
  <pre><code>FromNodeId  ToNodeId    Weight
  0   1   0.15
  0   2   0.95
  0   3   0.8
  0   4   0.5
  0   5   0.45
  0   6   0.35
  0   7   0.4
  0   8   0.6
  0   9   0.45
  0   10  0.7
  1   2   0.45
  1   11  0.7
  1   12  0.6
  1   13  0.75
  1   14  0.55
  1   15  0.1
  ...
  </code></pre>
  
  <p>I want to use Networkx graph format that can store such a large graph(about 10k nodes, 40k edges).</p>
  
  <pre><code>import networkx as nx
  import matplotlib.pyplot as plt
  
  g = nx.read_edgelist('test.txt', nodetype=int, create_using= nx.DiGraph())
  
  print(nx.info(g))
  nx.draw(g)
  plt.show()
  </code></pre>
  
  <p>When I run this code, nothing happens.
  I am using Spyder for editing.
  Could you help? Thanks!</p>