title: How can I set index while converting dictionary to dataframe?
body: <p>I have a dictionary that looks like the below</p>
  
  <pre><code>defaultdict(list,
          {'Open': ['47.47', '47.46', '47.38', ...],
           'Close': ['47.48', '47.45', '47.40', ...],
           'Date': ['2016/11/22 07:00:00', '2016/11/22 06:59:00','2016/11/22 06:58:00', ...]})
  </code></pre>
  
  <p>My purpose is to convert this dictionary to a dataframe and to set the 'Date' key values as the index of the dataframe.</p>
  
  <p>I can do this job by the below commands</p>
  
  <pre><code>df = pd.DataFrame(dictionary, columns=['Date', 'Open', 'Close'])
  
       0  Date                  Open    Close
       1  2016/11/22 07:00:00   47.47   47.48
       2  2016/11/22 06:59:00   47.46   47.45
       3  2016/11/22 06:58:00   47.38   47.38
  
  df.index = df.Date
  
       Date                  Date                  Open    Close
       2016/11/22 07:00:00   2016/11/22 07:00:00   47.47   47.48
       2016/11/22 06:59:00   2016/11/22 06:59:00   47.46   47.45
       2016/11/22 06:58:00   2016/11/22 06:58:00   47.38   47.38
  </code></pre>
  
  <p>but, then I have two 'Date' columns, one of which is the index and the other of which is the original column.</p>
  
  <p>Is there any way to set index <strong>while</strong> converting dictionary to dataframe, without having overlapping columns like the below?</p>
  
  <pre><code>     Date                  Close       Open
       2016/11/22 07:00:00   47.48       47.47
       2016/11/22 06:59:00   47.45       47.46
       2016/11/22 06:58:00   47.38       47.38
  </code></pre>
  
  <p>Thank you for reading this! :)</p>