title: Set dictionary keys as cells in dataframe column
body: <p>Please look at my code:</p>
  <pre><code>import pandas as pd
  
  my_dict = {
  1 :{'a':5 , 'b':10},
  5 :{'a':6 , 'b':67},
  7 :{'a':33 , 'b':9},
  8 :{'a':21 , 'b':37},
  }
  
  df = pd.DataFrame (my_dict).transpose()
  df['new'] = df.index
  
  print (df)
  </code></pre>
  <p>Here I convert dictionary to DataFrame and set index as new column.</p>
  <pre><code>    a   b  new
  1   5  10    1
  5   6  67    5
  7  33   9    7
  8  21  37    8
     
  </code></pre>
  <p>Can it be done in 1 line at the stage of converting a dictionary to a date without</p>
  <pre><code>df['new'] = df.index
  </code></pre>
  <p>I want to immediately recognize the major indices as cells of the new column.
  Something like</p>
  <pre><code>df = pd.DataFrame (my_dict, 'new' = list(my_dict.keys()).transpose()
  </code></pre>