Python If Statement Question

I'm trying to create a table plot by python script as below. PivotTable is a dynamic table, it sometimes include column ENT_MAT_CATG, sometimes not. This script is not working when it doesn't have ENT_MAT_CATG. Just need solution to make it work. from [login to view URL] import * from [login to view URL] import TablePlot def getDataTable(tableName): try: return [login to view URL][tableName] except: raise ("Error - cannot find data table: " + tableName) ## use table myDataTable = getDataTable("PivotTable") dataTable= [login to view URL][TablePlot]().[login to view URL] table = [login to view URL][TablePlot]() columns = [login to view URL] [login to view URL]() if [login to view URL]["PivotTable"].Columns["ROW_ID"] != None: [login to view URL][TablePlot]().[login to view URL]([login to view URL]["ROW_ID"]) if [login to view URL]["PivotTable"].Columns["MATERIAL_NUM"] != None: [login to view URL][TablePlot]().[login to view URL]([login to view URL]["MATERIAL_NUM"]) if [login to view URL]["PivotTable"].Columns["ENT_MAT_CATG"] != None: [login to view URL][TablePlot]().[login to view URL]([login to view URL]["ENT_MAT_CATG"]) for col in [login to view URL][TablePlot]().TableColumns: print [login to view URL]