title: speed up pandas concat function for 40 data frames each having 1 million rows and 100 columns
body: <p>I would like to speed up pandas <code>concat()</code> function for large data frames.</p>
  
  <p>I am having 40 data frames and each data frame is having say 1 million rows and 100 columns (columns can be anything: bool, string, integer etc). We have tried running it on clusters, using <code>dask</code> etc. Result is yet to come!</p>
  
  <p>Any idea would be highly appreciated.</p>