title: insert separator in data frame
body: <p>I am concatenating the multiple data frame one below another and i get the results like.</p>
  <pre><code>1.094  1.128  1.439 
  3.064  3.227  3.371  
  5.131  5.463  5.584  
  3.650  3.947  4.135   
  1.895  1.954  2.492 
  5.307  5.589  5.839
  </code></pre>
  <p>I want to put some separator in between the concatenated files so that expected output should be:</p>
  <pre><code>&gt;
  1.094  1.128  1.439 
  3.064  3.227  3.371
  &gt;  
  5.131  5.463  5.584  
  3.650  3.947  4.135
  &gt;   
  1.895  1.954  2.492 
  5.307  5.589  5.839
  &gt;
  </code></pre>
  <p>My code:</p>
  <pre><code>import numpy as np
  import pandas as pd
  #did some calcln and got x y z
  df=pd.concat([x,y,z], axis=0)
  df.to_csv('out.csv', index=False, header=False,sep='\t')
  </code></pre>