title: Counting number of elements in a dataframe column
body: <p>I have an R dataframe where I have imported a CSV file from some questionnaire data.</p>
  <p>One of my columns is called 'NewsMethods', where respondents have been asked to list methods they get news. This data in my dataset looks like this:</p>
  <ol>
  <li><p>Radio;Television;News websites (such as BBC News);Social Media websites or apps;Word of mouth</p>
  </li>
  <li><p>Radio;Television;News websites (such as BBC News);Social Media websites or apps;Word of mouth</p>
  </li>
  <li><p>Radio;Television;Social Media websites or apps;Word of mouth
  Television;Social Media websites or apps</p>
  </li>
  </ol>
  <p>... and so on.</p>
  <p>What I would like to be able to do replace each column with the number of elements it contains. For example I would like to replace the first list with the number 5.</p>
  <p>If anyone has any ideas for how I could do this I would be very grateful. TIA</p>
  <h3>Edit</h3>
  <pre><code>Radio;Television;News websites (such as BBC News);Social Media websites or apps;Word of mouth
  Radio;Television;News websites (such as BBC News);Social Media websites or apps;Word of mouth
  Radio;Television;Social Media websites or apps;Word of mouth
  Television;Social Media websites or apps
  Newspaper;Radio;Television;News websites (such as BBC News)
  Television
  Radio;Television;Word of mouth
  Television;Social Media websites or apps;Word of mouth
  Television;Word of mouth
  Newspaper;Radio;Television;News websites (such as BBC News);Social Media websites or apps;Word of mouth
  </code></pre>
  <p>I am expecting this to instead read:
  5
  5
  4
  2
  4
  1
  3
  3
  2
  6</p>