加密字符串,n/N退出
flag=True
while flag:
tag=input("字符串加密,退出请按N/n,其他请继续")
if tag in("n","N"):
flag=False
break
str_x=input("请输入要加密的字符串:")
for x in str_x:
if "a"<=x<="z":
x=chr(ord("a")+(ord(x)-ord("a")+4)%26)
print(x,end="")
elif"A"<=x<="Z":
x=chr(ord("A")+(ord(x)-ord("A")+4)%26)
print(x,end="")
elif"0"<=x<="9":
x=chr(ord("0")+(ord(x)-ord("0")+4)%10)
print(x, end="")
else:print(x,end="")