title: Using concat for a dictionary I get the error: first argument must be an iterable of pandas objects, you passed an object of type "DataFrame"
body: <p>I have a dictionary with dataframes, that looks like this:</p>
  
  <pre><code>dataframes = {'Df_20100101': DataFrame, 'Df_20100102': DataFrame, 'Df_20100103': DataFrame}
  </code></pre>
  
  <p>All dataframes have the same variables (Price, Volume and Date) and the same Index. I want to put all the different dataframes into 1 dataframe. I use the following code:</p>
  
  <pre><code>df = pd.concat([pd.concat(v,ignore_index=True) for k,v in dataframes.items()])
  </code></pre>
  
  <p>However, I get an error: <code>the first argument must be iterable of pandas objects, you passed an object of type "DataFrame"</code>.</p>
  
  <p>Is it because all the variables have the same Index?</p>
  
  <p>Can anyone help me out?</p>
  
  <p>Thank you!</p>