title: Set the currency symbol when writing with xlsxwriter
body: <p>I'm having trouble writing the currency symbol I want in my currency values with <code>xlsxwriter</code>.</p>
  
  <p>I followed the tutorial <a href="http://xlsxwriter.readthedocs.org/en/latest/tutorial02.html" rel="noreferrer">here</a> and I'm able to write out currency values with the correct formatting and a dollar sign (whether this is from the tutorial or excel's default settings I'm not sure).</p>
  
  <p>This works:</p>
  
  <pre><code>money = workbook.add_format({'num_format':'$#,##0.00'})
  </code></pre>
  
  <p>And it prints out a currency value with the dollar sign.</p>
  
  <pre><code>$1,000.00
  </code></pre>
  
  <p>But if I try to insert my own currency, let's say <code>R</code>:</p>
  
  <pre><code>money = workbook.add_format({'num_format':'R#,##0.00'})
  </code></pre>
  
  <p>I get this:</p>
  
  <pre><code>R1000
  </code></pre>
  
  <p>How can I set the currency symbol using xlsxwriter?</p>