Python Learning: Implementing a String for encryption

"' Title description 1, the input string is added and decrypted, and output. 2 The encryption method is: When the content is the English letter is replaced with the letter, and the letter is changed case, such as the letter A is replaced by B, the letter z is replaced by A; When the content is a number add 1, such as 0 replaces the replacement of 2,9 replacement 0, the other characters do not change. S ' ' # -*- coding: utf-8 -*-import re# determine if the letter is Def isletter (letters):     if len (letter)  != 1:        return 0     else:        num_re =  ' [a-z]| [A-z] '         pattern = re.compile (num_re)          result = re.match (Pattern, letter)          if result == None:             return 0        else:             return 1# determines if the letter is lowercase: def islower (Letters):    &nbsP;if letter.lower () ==letter:        return 1     else:        return 0# determine if the letter is Z/zdef isz (Letters):     if letter.lower () = = ' Z ':         return  1    else:        return 0# Encryption def for English letters  encryletter (letter):     if isz (letter) = = ' Z ':         if islower (letter) ==1:             return  ' A '         else:             return  ' A '     else:         if islower (letter) ==1:             return chr(Ord (letter) +1-32)         else:             RETURN CHR (ord (letter)) +1+32) #对数字进行加密def  encrynum (num):     if num==9:        return 0     else :        return int (num) +1#  Determine if it is a number: Def isnum (VAR):     if len (Var)  != 1:         return 0    else:         num_re =  ' [0-9] '         pattern = re.compile (num_re)         result = re.match (Pattern, var)          if result == None:             return 0        else:             return 1# encrypts a character def encrypt_single (character):     if isletter (character) ==1:        return encryletter ( character)     if isnum (character) ==1:         Return encrynum (character)     else:         The Return character "interface describes the:     implementation interface, each interface implements 1 basic operations:void encrypt  (char  Aucpassword[], char aucresult[]): Implement string encryption in this function and output description: 1, the string ends with a. 2, string maximum 100 characters. "' Def encrypt ():    while 1:         Unencrypt = input (' Enter the string to be encrypted, and the string length is not greater than 8: ')         if  Len (unencrypt) >8:             print ("String length greater than 8, please re-enter!") \ n ")             continue         else:            break     encrypt_str=[]    for i in range (Len (unEncrypt)):         encrypt_str.append (Encrypt_single (unEncrypt[i))      print (ENCRYPT_STR) Encrypt ()

Python Learning: Implementing a String for encryption