title: unable to load a simple csv in networkx in Python
body: <p>I am a complete noobie in Python, and I would like to study a dataset using the networkx package. I do not understand what is wrong here:</p>
  
  <p>I have a csv which looks like this (extract):</p>
  
  <pre><code>['152027', '-6167']
  ['152027', '-4982']
  ['152027', '-3810']
  ['152027', '-2288']
  ['152027', '-1253']
  ['152100', '-152100']
  ['152100', '-86127']
  </code></pre>
  
  <p>lets call this .csv file <code>nodes</code>. Numbers heres have no particular meanings. They are just anonymised names: so 152027 is a person that is connected to individual -6167, individual -4982, etc.</p>
  
  <p>I use the following code in Python</p>
  
  <pre><code>import csv
  import networkx as nx
  
  file = csv.reader(open('nodes', 'rb'), delimiter=',')
  
  G=nx.read_edgelist(file, delimiter=',',nodetype=float,encoding='utf-8')
  G.number_of_nodes()
  </code></pre>
  
  <p>and I get the sad <code>Out[71]: 0</code>
  I do not understand what is wrong here.
  Could you please help me?</p>