title: R convert list to character
body: <p>I have a problem in converting a list to a given character pattern.</p>
  
  <p>For example, I have a list in R: </p>
  
  <pre><code>tt &lt;- list(c("e7", "9f", "b3", "e5", "ae", "b6", "e5", "ba", "84"))
  </code></pre>
  
  <p>And I want to get the character like this: </p>
  
  <pre><code>'%e7%9f%b3%e5%ae%b6%e5%ba%84'
  </code></pre>
  
  <p>How can I do? Thanks.</p>