AEqMAbZv

1# Import the modules
2import sys
3
4while True:
5    userchoice = input("Encrypt or Decrypt [Enter to quit]?").upper()
6    if userchoice.startswith("E"):
7        prompt = "What is the plaintext to encrypt?"
8    elif userchoice.startswith("D"):
9        prompt = "What is the ciphertext to decrypt?"
10    else:
11        sys.exit()
12	
13    beforetext = input(prompt).upper()
14    if beforetext == "":
15        sys.exit()
16		
17    secretkey=""
18    while len(secretkey)<5:
19        secretkey = input("What is the secretkey (min of 5 characters)?").upper()
20    order = []
21    if (secretkey.isdigit()):
22        for el in secretkey:
23            if (secretkey.count(el)>1):
24                print("Invalid Key")
25                sys.exit()
26            order.append(el)
27    else:
28        tempSecret = list(secretkey)
29        tempKey = list(tempSecret)
30        tempKey.sort()
31        #tempKey.reverse()
32        for el in tempKey:
33            order.append(tempSecret.index(el))
34            tempSecret[tempSecret.index(el)] = "."
35    textGrid = []
36    aftertext = ""
37    tempText = ""
38    for letter in beforetext.upper():
39        if letter.isalpha():
40            tempText += letter
41        elif letter.isspace():
42            pass
43        else:
44            print ("Invalid character skipped: ", letter)
45    while (len(tempText)%len(secretkey) != 0):
46        tempText += "X" 			#chr(random.randint(65,90))
47    while(len(tempText) > 0):
48        textGrid.append(list(tempText[:len(secretkey)]))
49        tempText = tempText[len(secretkey):]
50        #print (order)
51    aftertext = ""
52    if userchoice.startswith("E"):
53        for mycol in range(0,len(order)):
54            for myrow in range(0,len(textGrid)):
55                aftertext += textGrid[myrow][order[mycol]]
56    else:
57        tempGrid = textGrid
58        cnum = 0
59        for mycol in range(0,len(order)):
60            for myrow in range(0,len(textGrid)):
61                tempGrid[myrow][order[mycol]] = beforetext[cnum]
62                cnum += 1
63        for myrow in range(0,len(tempGrid)):
64            for mycol in range(0,len(order)):
65                aftertext += tempGrid[myrow][mycol]
66                        
67    print (beforetext," => ",aftertext)