I can't get my python encryption program to work properly

Question

I've seen other programs that encrypt text, however they tend to be quite long winded - and I'm relatively new to python. I've had a go at encrypting something (It is quite simple) and I can get each character turned into ASCII, it's value changed and then turned back. But when I run the code, only the last character is displayed in the list, why is this and what have I done wrong???

message = input('What should I encrypt? ')

for i in range(len(message)):
    num = ord(message[i])
    num += 3
    Chr = chr(num)
    Message = []
    Message.append(Chr)
print(Message)

Answer 1

message = input('What should I encrypt? ')
secret = []

for i in range(len(message)):
    num = ord(message[i])
    num += 3

    secret.append(chr(num))
print(secret)

You were redefining Message (in my code secret) over and over through each iteration, therefore when the for-loop has ended you got only the last character. Moving the Message = [] before the for-loop fixes the issue.

You can iterate through characters in the string directly (when you do not need the index), like for char in message: do_stuff().

Example here:

message = input('What should I encrypt? ')
secret = []

for char in message:
    num = ord(char) + 3
    secret.append(chr(num))

print(secret)