我正在使用Python SAX解析器解析一个文件夹中的xml文件，并使用Pandas将输出写入CSV，但我只从CSV中的最后一个文件中获取数据。
我是Python新手，这是我第一次尝试SAX解析
文件读取：

for dirpath, dirs, files in os.walk(fp1): 
          for filename in files:
            print(files)
            fname = os.path.join(dirpath,filename)
            if fname.endswith('.xml'):
              print(fname)
              #for count in files:
            parser.parse(fname)

def characters(self, content):
        rows = []
        cols = ["ReporterCite","DecisionDate","CaseName","FileNum","CourtLocation","CourtName","CourtAbbrv","Judge","CaseLength","CourtCite","ParallelCite","CitedCount","UCN"]
        #ReporteCite, DecisionDate, CaseName, FileNum, CourtLocation, CourtName, CourtAbbrv, Judge, CaseLength, CourtCite, ParallelCite, CitedCount, UCN             

        rows.append({"ReporterCite":self.rc,
                     "DecisionDate": self.dd,
                     "CaseName": self.can,
                     "FileNum": self.fn,
                     "CourtLocation": self.loc,
                     "CourtName": self.cn,
                     "CourtAbbrv": self.ca,
                     "Judge": self.j,   
                     "CaseLength": self.cl,
                     "CourtCite": self.cc,
                     "ParallelCite": self.pc,
                     "CitedCount": self.cd,
                     "UCN": self.rn})

        #print(rows)
        df = pd.DataFrame(rows, columns=cols)
        df.to_csv(fp2,index=False)