python提取内容写入txt，生成了txt文件但是为空，请问要怎么解决啊？

各位大神，写入txt，生成了txt文件但是为空，请问要怎么解决啊？
      

  with open("PATH.txt","w") as f:
            while True:
                for i in range(self.ldir_txt):
                    print(self.dirname_txt[i])
                    total=len(self.list_txt[i])
                    for loop_menu in range(total):
                        if  seekA in self.list_txt[i][loop_menu]:
                            f.write('##########################'+'\n'+\
                                str(self.dirname_txt[i])+'\n'+\
                                 '##########################'+'\n')
                            for loop_out in range(loop_menu,0,-1):
                                if "#" in self.list_txt[i][loop_out] or 'exit' in self.list_txt[i][loop_out]:
                                    for loop_in in range(loop_out,total):
                                       print(self.list_txt[i][loop_in])
                                       f.write(self.list_txt[i][loop_in])
                                       if "#" in self.list_txt[i][loop_in] or 'exit' in self.list_txt[i][loop_in] :
                                           break
                                if "#" in self.list_txt[i][loop_out] or 'exit' in self.list_txt[i][loop_out]:
                                    break
                            break
              
                if seekA=='0':
                    break
        f.close()
        return f