Python Caesar cipher with two keys

Question

I want to write a caesar cipher with two keys; one for vowels and another for consonants.

I have words with only capital letters. I've written some code, but I know this is wrong. I want to follow that way. Can someone help me:

def ceasar(word, key1, key2): 
    c = "" 
    for i in range(len(word)): 
        zn = word[i]
        for x in zn:
                        if x=="A" or x=="E" or x=="I" or x=="O" or x=="U":
                                c += chr((ord(zn) + key1-65) % 26 + 65)                               
                else:
                                c += chr((ord(zn) + key2-65) % 26 + 65)


    return c

score 1 · Accepted Answer · answered Apr 17 '20 at 13:21

Just catering for upper case letters and no other characters, you can get it working by simplifying it a little to:

def caesar(word, key1, key2):
    c = ""
    for x in word:
        if x in "AEIOU":
            c += chr((ord(x) + key1 - 65) % 26 + 65)
        else:
            c += chr((ord(x) + key2 - 65) % 26 + 65)
    return c

You had two loops, but that's unnecessary as in your code, zn is only a single character anyway, so doesn't need a second loop.

I've simplified your vowel check, as you can check if a character appears in a string much more simply than using multiple or conditions.

It's also much more common in Python to loop over an iterator by value, rather than by looping over an index and then using that index value to access the iterator.

What does " a=[ ord(i) for i in word ] " means in Python, and how else do you write it? — piteer, Apr 17 '20 at 15:00
It's a list comprehension. The alternative would be to create an empty list `a`, then have a loop of `for i in word:` and inside the for loop do `a.append(ord(i))` to build the list. You can find out more about list comprehensions and loops in general [here](https://realpython.com/list-comprehension-python/#using-list-comprehensions) — David Buck, Apr 17 '20 at 15:35

Python Caesar cipher with two keys

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