title: Closing files in openpyxl
body: <p>Neither of these process, as would be expected reading the documentation:</p>
  
  <pre><code>worksheet.close()
  workbook.close()
  </code></pre>
  
  <p>Is there a way to close files once done in openpyxl? Or is it handled automatically when the program quits? I dont want to leave spreadsheets left hanging in memory.</p>