Python如何实现的文本简单可逆加密算法

# -*-coding:utf-8 -*-

importsys

reload(sys)

sys.setdefaultencoding('utf8')

#加密

defjiami():

  filename=raw_input('please input file:n')

  whileTrue:

    try:

      password=int(raw_input('input number pass word:n'))

      break

    except:

      print'please input number:n'

  fileword=open(filename,'r')

  num=filename.rfind('.')

  newfilename=filename[:num]+'[加密]'.encode('gbk')+filename[num:]

  content=fileword.read(1)

  newfileword=open(newfilename,'a+')

  whilelen(content)>0:

    contentInt=ord(content)

    newContent=contentInt+password

    c=chr(newContent)

    newfileword.write(c)

    content=fileword.read(1)

  newfileword.close()

  fileword.close()

#解密

defjiemi():

  filename=raw_input('please input file:n')

  whileTrue:

    try:

      password=int(raw_input('input number pass word:n'))

      break

    except:

      print'please input number:n'

  fileword=open(filename,'r')

  num=filename.rfind('.')

  num2=filename.rfind('[')

  newfilename=filename[:num2]+'[解密]'.encode('gbk')+filename[num:]

  content=fileword.read(1)

  newfileword=open(newfilename,'a+')

  whilelen(content)>0:

    contentInt=ord(content)

    newContent=contentInt-password

    c=chr(newContent)

    newfileword.write(c)

    content=fileword.read(1)

  newfileword.close()

  fileword.close()

whileTrue:

  index=int(raw_input('---请输入命令,1为加密 2为解密 3为退出---n'.encode('gbk')))

  ifindex==1:

    jiami()

  elifindex==2:

    jiemi()

  elifindex==3:

    exit(0)

else:

    pass