title: Custom output of edgelist in networkx
body: <p>I am trying to implement tarjan's algorithm for practice. 
  I decided to generate a random graph to give as input to the algorithm, adding one edge at a time.</p>
  
  <p>I generated the random graph and saved it in a file, as shown below</p>
  
  <pre><code>from networkx import *
  import sys
  import matplotlib.pyplot as plt
  
  n = 10  # 10 nodes
  m = 20  # 20 edges
  
  G = gnm_random_graph(n, m)
  
  # print the adjacency list to a file
  try:
      nx.write_edgelist(G, "test.edgelist", delimiter=',')
  except TypeError:
      print "Error in writing output to random_graph.txt"
  
  fh = open("test.edgelist", 'rb')
  G = nx.read_adjlist(fh)
  fh.close()
  </code></pre>
  
  <p>The output that I got in the test.edgelist file is something like this.</p>
  
  <pre><code>0,4,{}
  0,5,{}
  0,6,{}
  1,8,{}
  1,3,{}
  1,4,{}
  1,7,{}
  2,8,{}
  2,3,{}
  2,5,{}
  3,8,{}
  3,7,{}
  4,8,{}
  4,9,{}
  5,8,{}
  5,9,{}
  5,7,{}
  6,8,{}
  6,7,{}
  7,9,{}
  </code></pre>
  
  <p>How ever, in the tarjan's algorithm that I've implemented, the input is in the format</p>
  
  <pre><code>add_edge(1,2)
  add_edge(2,3)
  ....
  </code></pre>
  
  <p>I wish to use the randomly generated graph in a loop to give as input.</p>
  
  <p>How do i not get the {}?
  Also, if there is some better way to implement this, please help, since, for a massive dataset, it'll be difficult to save it an a single list(add_edge() adds the edge to a list)</p>