When opening e.g. a spreadsheet with pywin32, I found two options to do so:
excel1 = win32com.client.DispatchEx(\'Excel.Application\') wb = excel1.Workbooks.Open
It depends on what you want. If Excel is already open, using dispatch will create a new tab in the open Excel instance. If Excel is already open, using dispatchEx will open a new instance of Excel.