Excel - Power query data refresh via Python

I know this is an old question, but I just came across it. You need to close the Excel Workbook object before you quit Excel. Oddly, when you quit the Excel object the Excel Workbook still remains in memory and operating -- it's a little confusing. You should replace the wb.Save() command with the wb.Close(True) command.

import win32com.client
import time
xl = win32com.client.DispatchEx("Excel.Application")
wb = xl.workbooks.open(fileName)
xl.Visible = True
wb.RefreshAll()
wb.Close(True)
xl.Quit()

That said, keeping the os.system("taskkill /f /im excel.exe") as a backup is good as well. I've found the Close and Quit commands are not fool proof and can cause problems if you don't periodically kill the outstanding Excel tasks.

In addition to the above, consider this.

IF the query property "Enable Refresh in the Background" ENABLED THEN wb.refreshAll() will immediately return.

There are ways to check the refresh status e.g. wb.Sheets.QueryTables.QueryTable.Refreshing but this doesn't work for Power Queries because wb.QueryTables returns null, even when called individually iterated over the sheets and querytables

Therefore, the only workaround for this is to DISABLE "Enable Refresh in the Background" in ALL the queries for refreshAll

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