Answer: Secret Code #233

The secret message says:

ASTRONAUT

Letter by letter

Secret letter	F	G	H	I	L	M	Z
Real letter	U	T	S	R	O	N	A

Decode it with Python

This program does the decoding for you. Change the secret and the code to crack other messages!

secret = "ZHGILMZFG"
message = ""

for letter in secret:
    if letter.isalpha():
        position = ord(letter) - ord("A")
        message = message + chr(ord("Z") - position)
    else:
        message = message + letter

print(message)

When you run it, it prints:

ASTRONAUT