title: Getting the excel file after df.to_excel(...) with Panda
body: <p>I am using Pyrebase to upload my files to Firebase.</p>
  
  <p>I have a DataFrame <code>df</code> and convert it to an Excel File as follows:</p>
  
  <pre><code>writer      = ExcelWriter('results.xlsx')
  excelFile   = df.to_excel(writer,'Sheet1')
  
  print(excelFile)
  
  # Save to firebase
  childRef        = "path/to/results.xlsx"
  
  storage         = firebase.storage()
  storage.child(childRef).put(excelFile)
  </code></pre>
  
  <p>However, this stores the Excel file as an Office Spreadsheet with zero bytes. If I run <code>writer.save()</code> then I do get the appropriate filetype (<code>xlsx</code>), but it is stored on my Server (which I want to avoid). How can I generate the right filetype as one would do with <code>writer.save()</code>?</p>
  
  <p>Note: <code>print(excelFile)</code> returns <code>None</code></p>