python 文件去重

import time

def main(file_name):
  try:
    with open(file_name, 'r', encoding='utf-8') as f:
      lines = f.readlines()
      print(lines)

      start=time.time()
      print('总数:',len(lines))

      new_lst=list(set(lines))
      print('去重后:',len(new_lst))
      print(time.time()-start,'秒')

      with open(file_name,'w', encoding='utf-8') as f:
        f.write(''.join(new_lst))
      print('文件保存到:',file_name)

  except Exception as e:
    print('错误的文件路径！！！', e)


if __name__ == '__main__':
  main('a.txt')