title: Remove single letters from strings in Pandas dataframe
body: <p>I have a DataFrame where a column is filled with strings. I want to remove any appearance of single letters from the column. So far, I have tried:</p>
  
  <pre><code>df['STRI'] = df['STRI'].map(lambda x: " ".join(x.split() if len(x) &gt;1)
  </code></pre>
  
  <p>I wish to input <code>ABCD X WYZ</code> and get <code>ABCD WYZ</code>.</p>