3.csv") |&gt; mutate(x = parse_date(x, "%d %B %Y")) </td>
  </tr>
  <tr>
   <td style="text-align:left;"> controlling-column-types-15 </td>
   <td style="text-align:left;"> exercise </td>
   <td style="text-align:left;"> read_csv("data/ex_3.csv") |&gt; mutate(x = parse_date(x, "%d %B %Y"), z = parse_number(z)) </td>
  </tr>
  <tr>
   <td style="text-align:left;"> reading-data-from-multiple-fil-1 </td>
   <td style="text-align:left;"> exercise </td>
   <td style="text-align:left;"> list.files("data