title: Pandas / xlsxwriter writer.close() does not completely close the excel file
body: <p>I'm trying to modify manually an excel file after creating it with a python script. Unfortunately, if the script is still running, a sharing file violation error message appears when trying to save it with the same name.</p>
  
  <p>Everything runs smoothly in the code. The file is created, filled and saved. I can open it and work on it but can't overwrite it under the same name if the script is still running.</p>
  
  <pre class="lang-py prettyprint-override"><code>outpath = filedialog.asksaveasfile(
      mode="wb",
      filetype=[("Excel", ("*.xls", "*.xlsx"))],
      defaultextension=".xlsx",
  )
  writer = pd.ExcelWriter(outpath, engine="xlsxwriter")
  df1.to_excel(writer, sheet_name="Results")
  writer.save()
  writer.close()
  </code></pre>
  
  <p>I expect python to fully close the excel file and let me overwrite on it while the script is still running</p>