title: column index in splited dataindex variable
body: <p>I have a dataframe like df</p>
  <pre><code>ID  years   note    statut
  1   0       16       8
  7   0       1       4
  …
  2   2       2      5
  3   2       8      4
  …
  </code></pre>
  <p>I want 1 df in years in ouput</p>
  <pre><code>df0
  ID  years   note0   statut0
  1   0   16  8
  7   0   1   4
  
  df2
  ID  years   note2   statut2
  2   2   2   5
  3   2   8   4   
  </code></pre>
  <p>My code is</p>
  <pre><code>   liste &lt;- list(1,2,3,4,5) 
      for (i in seq_along(liste)){   
         df[[i]] &lt;- df %&gt;%
            filter(years==i) %&gt;%
            renames(note[[i]]=note) 
      }
  </code></pre>
  <p>but I have an error like:  Error in <code>[[&lt;-.data.frame</code>(<code>*tmp*</code>, i,....</p>
  <p>It's possible to split by years but how to index columns</p>
  <pre><code>split(df, df$years)
  </code></pre>
  <p>Thanks</p>