title: how to make a list from pandas if the index is timestamp
body: <p>Here is my dataframe</p>
  
  <pre><code>ord_datetime
  2019-05-01    22.483871
  2019-05-02    27.228070
  2019-05-03    30.140625
  2019-05-04    32.581633
  2019-05-05    30.259259
  </code></pre>
  
  <p>if i do code like this </p>
  
  <pre><code>b=[]
  
  b.append((df.iloc[2]-df.iloc[1])/(df.iloc[1]))
  
  print(b)
  </code></pre>
  
  <p>output is </p>
  
  <pre><code>[Ordered Items    0.106969
  dtype: float64]
  </code></pre>
  
  <p>I want an output like <code>0.106969</code> only</p>
  
  <p>How can i do that?</p>