python如何删除文件中重复的字段

import csv

filetxt1 = 'E:/gg/log/log1.txt'
filecsv1 = 'E:/gg/log/log1.csv'
filecsv2 = 'E:/gg/log/log2.csv'
filecsv3 = 'E:/gg/log/log3.csv'


class operFileCsv():
 def __init__(self, filename=None):
  self.filename = filename

 def readCsvFile(self):
  readCsvHandler = open(self.filename, 'r')
  filelines = csv.reader(readCsvHandler, dialect='excel')
  for fileline in filelines:
   print(fileline)
  readCsvHandler.close

 def writeCsvFile(self, writeline):
  writeCsvHandler = open(self.filename, 'a', newline='')
  csvWrite = csv.writer(writeCsvHandler, dialect='excel', )
  csvWrite.writerow(writeline)
  writeCsvHandler.close()


class getLogBuffFromFile():
 def __init__(self):
  self.logBuff1 = []

 def getLog1Buff(self, filename):
  with open(filename) as filehandler:
   while True:
    logOneLine = filehandler.readline().strip()
    if not logOneLine:
     break
    self.logBuff1.append(logOneLine)
  # print('TRACE: The log1 has ', len(self.logBuff1), ' lines.')
  return self.logBuff1

 def getLog2Buff(self, logOneLine):
  pass


class deleteIterantLog():
 def __init__(self):
  self.logBuff1List = None
  self.logBuff2OneLine = None

 def deleteProcedure(self, oldlog, newlog, createlog):
  self.logBuff1List = getLogBuffFromFile().getLog1Buff(oldlog)
  self.dealProcedure(newlog, createlog)

 def dealProcedure(self, file1name, file2name):
  with open(file1name, 'r') as readCsvHandler:
   filelines = csv.reader(readCsvHandler, dialect='excel')
   for fileline in filelines:
    if fileline[1] not in self.logBuff1List:
     operFileCsv(file2name).writeCsvFile(fileline)


if __name__ == '__main__':
 deleteIterantLog().deleteProcedure(filetxt1, filecsv2, filecsv3)

import os,sys,datetime
import codecs
with open('aaaaa.txt', 'r') as f:  #读入文本中的文件
 l = f.readlines() # txt中所有字符串读入data
 x=set(l[0])
 for i in range(1,len(l)):
  x.update(l[i])
 s="".join(list(x))
 print(s)
with open('result.txt','wb') as f1: #把结果写到文件result中
 b=bytes(s,encoding="utf-8") 
 f1.write(b)