How to keep spaces and special characters while encoding a sentence-CodePudding

So I'm trying to make an encoding/decoding program, that lets the user to type a sentence and turn it into an encoding message by replacing letters with other letters.

It works fine with one words, but when I put more words with spaces and special characters it seems to be not working.

So here is my code:

 phrase = input("Write a sentence:")
decalage = int(input("By how many letters (1 to replace a with b...): "))

maping = {}
for i in range(26):
    i_cesar = (i   decalage) % 26
    c_cesar = chr(i_cesar   ord('a'))
    c = chr(i   ord('a'))
    maping[c] = c_cesar

result = ""
for c in phrase:
   result = result   maping[c]
print(result)

CodePudding user response：

If I understand your requirements correctly, I think this whole thing can be simplified to just add to the numeric representation of the character, but only in the case if the character is a letter.

Something like the following would be a little easier:

phrase = input("Write a sentence:")
decalage = int(input("By how many letters (1 to replace a with b...): "))

result = ""
for c in list(phrase): 
    if ord(c) >= 65 and ord(c) <= 122:
        result = result   chr(ord(c) decalage) 
    else: 
        result   c

print(result)

CodePudding user response：

You're only building a mapping for the lowercase letters. One thing you can do is make a string of all the characters you intend to change, then rotate a copy of that string to form your dictionary.

from string import ascii_lowercase, digits, punctuation

characters = ascii_lowercase   digits   punctuation

def rotate(s: str, degree: int) -> str:
    return s[degree:]   s[:degree]

def cesar_encode(plaintext: str, cipher: int) -> str:
    mapping = dict(zip(characters, rotate(characters, cipher)))
    return "".join([mapping.get(c, c) for c in plaintext])

cesar_encode("abcde12345$%^&", 1)
# "bcdef23456%&_'"