title: How to set a column as an index in dateframe in pandas
body: <p>I have a dict like this:</p>
  
  <pre><code>   dict = {'open': 245.04, 'high': 245.769, 'low': 244.7, 'close': 245.51, 'volume': 1489478, 'datetime': 1584451800000}
  </code></pre>
  
  <p>I want to convert it into a dateframe data and set datetime as an index.</p>
  
  <p>So I tried:</p>
  
  <pre><code>data=pd.DataFrame.from_dict(dict,orient='index')
  </code></pre>
  
  <p>And then I received:</p>
  
  <pre><code>                     0
  open      2.450400e+02
  high      2.457690e+02
  low       2.447000e+02
  close     2.455100e+02
  volume    1.489478e+06
  datetime  1.584452e+12
  </code></pre>
  
  <p>How to set datetime as an index?</p>