Ceaser cipher program

[oli_action]

Hi eveyone,

I'm currently working on a ceasar cipher project. I pretty much have the basic structure down and the program is able to auto-encrypt the input ( given text ) by +1 position. I can change the positioning either by "int(input)"option or by directly adding to the code. Now I would like to change the position of each letter separately as follows: +1 +2 +3 +4 +5 etc.

Example 1 with input option:

def ascii_code(message):
    print("Decryption with ASCII-output")
    for symbol in message:
        print(ord(symbol), end = " ")

    print("\n")

def caesar(message):
    print("Caesar Decryption:")
    shift = int(input("Please enter the shift value: "))
    for letter in message:
        if letter.isupper():
            print(chr((ord(letter)+ shift - 65) % 26 + 65), end = " ")
        else:
            print(chr((ord(letter)+ shift - 97) % 26 + 97), end = " ")


    print("\n")

enter = input("Please enter your message: ")
print("The original message is:", enter, "\n")

ascii_code(enter)
caesar(enter)

Example 2 with manual entry option with shift value +1:

def ascii_code(message):
    print("Decryption with ASCII-output")
    for symbol in message:
        print(ord(symbol), end = " ")

    print("\n")

def caesar(message):
    print("Caesar Decryption:")
    shift = 1 
    for letter in message:
        if letter.isupper():
            print(chr((ord(letter)+ shift - 65) % 26 + 65), end = " ")
        else:
            print(chr((ord(letter)+ shift - 97) % 26 + 97), end = " ")


    print("\n")

enter = input("Please enter your message: ")
print("The original message is:", enter, "\n")

ascii_code(enter)
caesar(enter)

My message is: Iamsecret. Currently the output is Jbntfsfu using +1. I would like the encryption to be +1 J / +2 c / +3 p and so on. I've tried numerous routes, but i keep . Do i have to add another loop to the function or do I change the current loop? Any hints, help would be much appreciated.


Thanks

[Larz60+]

I tried using code from w3schools tutorial here: https://www.w3resource.com/python-exerci...ise-25.php
here's the code (modified fro your message and shift value:

#https://gist.github.com/nchitalov/2f2b03e5cf1e19da1525
def caesar_encrypt(realText, step):
	outText = []
	cryptText = []
	
	uppercase = ['A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z']
	lowercase = ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z']

	for eachLetter in realText:
		if eachLetter in uppercase:
			index = uppercase.index(eachLetter)
			crypting = (index + step) % 26
			cryptText.append(crypting)
			newLetter = uppercase[crypting]
			outText.append(newLetter)
		elif eachLetter in lowercase:
			index = lowercase.index(eachLetter)
			crypting = (index + step) % 26
			cryptText.append(crypting)
			newLetter = lowercase[crypting]
			outText.append(newLetter)
	return outText

code = caesar_encrypt('Iamsecret.', 1)
print()
print(code)
print()

The results are the same as what you get, but in a list, and
no 'c' at end

Output:
theirs: ['J', 'b', 'n', 't', 'f', 'd', 's', 'f', 'u']
yours:  J b n t f d s f u c

[oli_action]

Hi Larz60+

thanks for the quick reply. That has the same output as my original code though. The user must be able to add his/her own message to encrypt. What is most important though is that the output should to be the following:

example:

I a m s e c r e t
+1 +2 +3 +4 +5 +6 +7 +8 +9

output:
J c p w j i y m c

I can't figure this out.

[TomToad]

Take a look at what your code does each step. First, you assign the value 1 to shift. Then, each iteration of the loop, you add the value of shift to the next letter. So the first letter has 1 added to it as shift equals 1, the second letter has 1 added to it because shift still equals 1, the third letter has 1 added to it because shift still equals 1, etc...

But you want to have 1 added to the first, 2 added to the second, 3 added to the third, etc... So what needs to change each loop? How would you change it, and where in the code would be the best place to change it?

[Larz60+]

my code was just to show you that your code was almost ok, however you have one additional output.
as far as input is concerned, put your code lines 20 - 24 into a loop, preferably all within a function.

[oli_action]

Hi guys, yea I got it. Not sure if this is the optimal way, but it works. Thanks again for the help :)

def caesar(message):
    print("Caesar Decryption:")
    value = 1
    for letter in message:
        if letter.isupper():
            print(chr((ord(letter)+ value - 65) % 26 + 65  ), end = " ")
        else:
            print(chr((ord(letter)+ value - 97 ) % 26 + 97 ), end = " ")
        value = value + 1
    print("\n")

enter = input("Please enter your message: ")
caesar(enter)