Programme chiffrement César

phrase = input("Ecrivez une phrase:")
decalage = int(input("Valeur du décalage?"))
maping = {}
for i in range(26):  
    i_caesar = (i + decalage) % 26
    c_caesar = chr(i_caesar + ord('A'))
    c = chr(i + ord('A'))
    maping[c] = c_caesar

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