if os.path.exists('excelsheet.xlsm'):
    xl = win32com.client.Dispatch('Excel.Application')
xl.Workbooks.Open(Filename='C:\\Full Location\\To\\excelsheet.xlsm', ReadOnly=1
    )
xl.Application.Run('excelsheet.xlsm!modulename.macroname')
xl.Application.Quit()
del xl
Running an Excel macro via Python?