title: How to 'raw text' a variable in Python?
body: <p>I am opening a workbook in <code>openpyxl</code> thus:        </p>
  
  <pre><code>wb = load_workbook(r'seven.xlsx', data_only=True)
  </code></pre>
  
  <p>The name of the spreadsheet won't always be know in advance, so I need to rewrite this hardcoding to allow for a variable, while still maintaining the <code>r</code>?</p>
  
  <p>If my variable name is sheet, then:</p>
  
  <pre><code>wb = load_workbook(sheet, data_only=True)
  </code></pre>
  
  <p>will omit the <code>r</code>.</p>
  
  <p>And obviously I cannot do:</p>
  
  <pre><code>wb = load_workbook(r'sheet', data_only=True)
  </code></pre>
  
  <p>How do we achieve the prepending of r to a variable / how do we wrap a vriable within <code>r''</code>?</p>