title: How to merge several Excel sheets from different files into one file
body: <p>Each source file contains only one sheet. All I want is to combine these sheets into a single file. I suppose I'll have to use win32com.  </p>
  
  <p>Does anyone know how?</p>
  
  <p>Update: the sheets to be combined have extensive conditional formatting that I'd like to keep. The following code could only combine them with all conditionally formatting information lost.</p>
  
  <pre><code>from openpyxl import load_workbook, Workbook
  import os
  
  fwb = Workbook()
  
  wb = load_workbook('CM1.xlsx')
  ws1 = wb.active
  wb = load_workbook('CM2.xlsx')
  ws2 = wb.active
  wb = load_workbook('CM3.xlsx')
  ws3 = wb.active
  
  fwb.add_sheet(ws1)
  fwb.add_sheet(ws2)
  fwb.add_sheet(ws3)
  
  fwb.save('CM.xlsx')
  </code></pre>