pyparsing - 在pyparsing python中从Word（字母数字+'_。'）中排除预定义的关键字

Question

selectStmt=(select +
        ('*' |delimitedList(functionbody|column)).setResultsName("Columns") + Optional((_as+table.setResultsName("Aliases"))|table.setResultsName("**Aliases1**"),'')+
        Optional(_into+('*' |columns).setResultsName("Columns"),'')+
        _from +
        table.setResultsName("Tables",listAllMatches=True)+Optional((_as+table.setResultsName("Aliases"))|table.setResultsName(**Aliases2**),'')+
        Optional(where + Group(whereExpr), '').setResultsName("where") +
        Each([Optional(groupby + columns("groupby")+Optional(_asc|_desc,''),'').setDebug(False),
            Optional(orderby + columns("orderby"),'').setDebug(False),Optional(_limit+columnVal,'')
            ])).setResultsName("Select",listAllMatches=True)+Optional((_union_all|_union)+selectStmt,'').setResultsName("Union")

所以如果我匹配查询

select count(id) sellercount
            into v_photocount
            from carphotos photos
            where inquiryid = v_inquiryid
                and isdealer = (
                                case 
                                when v_sellertype = 1  then 1
                                                      else 0
                                end
                               )
                and isactive = 1
                and isapproved = 1;

然后，sellercount 与 _into 匹配，照片与 where 匹配。我怎样才能避免这种情况