Cannot select specific excel sheet in Python with OLE Object

It took time and I finally found the solution.

To select a specific sheet of an excel file, an Activate method must be called. Per Microsoft doc: "Calling this method is equivalent to clicking the sheet's tab".

My working codes is below:

def openExcel():
    fileName = "C:\\Works\\Testcases.xlsx"
    excel = Sys.OleObject["Excel.Application"]
    excel.Visible = True
    try:
        workBook = excel.Workbooks.Open(fileName) 
    except (RuntimeError):
        Log.Warning("File " + fileName + " was not found.");
    numFound = workBook.Sheets.Count
    Log.Message("This workbook has " + str(numFound) + " worksheets.")
    for i in range(0,numFound):
        sheetName = workBook.Sheets.Item[i+1].Name
        Log.Message(str(sheetName))
        excel.Worksheets.Item[sheetName].Activate() #Clicking the tab with Activate Method
        RowCount = excel.ActiveSheet.UsedRange.Rows.Count
        ColumnCount = excel.ActiveSheet.UsedRange.Columns.Count
        Log.Message("Row Count = " + VarToStr(RowCount))
        Log.Message("Col count = " + VarToStr(ColumnCount))
        cell = VarToStr(excel.Cells.Item[2, 1])
        Log.Message(cell)
    excel.Quit()