title: Select rows when they contain certain string using R
body: <p>I have a data frame below: </p>
  
  <pre><code>Acct &lt;- c(1001, 1002, 1003)
  Tran &lt;- c(01, 02, "ALL")
  Group &lt;- c(01, 01, 02)
  DF1 &lt;- data.frame(Acct, Tran, Group)
  </code></pre>
  
  <p>Now I need to select the rows where "ALL" shows up. The result should look like: </p>
  
  <pre><code> Acct |  Tran  | Group
   1003 |   ALL  |  2
  </code></pre>
  
  <p>One thing to mention is that "ALL" can be in any column (not just "Tran") and there may be any number of columns.</p>