title: Put multiple data frames into list (smart way)
body: <p>Is it possible to put a lot of data frames into a list in some easy way?
  Meaning instead of having to write each name manually like the following way:</p>
  
  <pre><code>list_of_df &lt;- list(data_frame1,data_frame2,data_frame3, ....)
  </code></pre>
  
  <p>I have all the data frames loaded into my work space.
  I am going to use the list to loop over all the data frames (to perform the same operations on each data frame).</p>