title: merging a list of dataframes with dplyr
body: <p>I have a list of 7 data frames (list_df) which I would like to merge into a single data frame (df_tot). The data frames, for the most part, have the same column names - with a couple exceptions - and are comprised mostly of factors with different levels between data frames (see pngs link of structure and head).</p>
  
  <p>I am using the <code>rduce</code> function in purrr as so: <code>df_tot &lt;- reduce(list_df, full_join)</code>. However, this causes my pc to crash...</p>
  
  <p>Any help appreciated.</p>
  
  <p><img src="https://i.stack.imgur.com/LJGyd.png" alt="structure"></p>
  
  <p><img src="https://i.stack.imgur.com/K3Rnp.png" alt="test head"></p>