python实现移位加密和解密

本文实例为大家分享了python实现移位加密和解密的具体代码，供大家参考，具体内容如下

代码很简单，就不多做解释啦。主要思路是将字符串转为Ascii码，将大小写字母分别移位密钥表示的位数，然后转回字符串。需要注意的是，当秘钥大于26的时候，我使用循环将其不断减去26，直到密钥等效小于26为止。

def encrypt():
 temp = raw_input("Please input your sentence: ")
 key = int(raw_input("Please input your key: "))
 listA = map(ord,temp)
 lens = len(listA)
 for i in range(lens):
   a = listA[i]
   if 65 <= a <= 90:
     a += key
     while a > 90:
       a -= 26
   elif 97 <= a <= 122:
     a += key
     while a > 122:
       a -= 26
   listA[i] = a
 listA = map(chr,listA)
 listA = ''.join(listA)
 print listA

def unencrypt():
 temp = raw_input("Please input your sentence: ")
 key = int(raw_input("Please input your key: "))
 listA = map(ord, temp)
 lens = len(listA)

for i in range(lens):
   a = listA[i]
   if 65 <= a <= 90:
     a -= key
     while a < 65:
       a += 26
   elif 97 <= a <= 122:
     a -= key
     while a < 97:
       a += 26
   listA[i] = a
 listA = map(chr, listA)
 listA = ''.join(listA)
 print listA

a = int(raw_input("input 0 to encrypt and 1 to unencrypt"))

if a == 0:
 encrypt()
elif a == 1:
 unencrypt()

效果

来源：https://blog.csdn.net/St_laurence/article/details/83352951