run this to decode

puzzle.py

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""This is a rot-13 encoded puzzle. Interestingly, this is how the `this` module is implemented 
in Python.

Did you know that the `this` module breaks the Zen of Python in almost *every* possible way?

Run this on Python Anywhere and you can see the output on your phone. 
Here's a `link <https://www.pythonanywhere.com/user/stonecharioteer/shares/61f863777d13449599ecab5bf11ff34d/>`_.

Or, you can clone this gist and run it on your laptop."""


s = """Jrypbzr gb gur svefg Ivfn OnatClcref zrrghc rirelbar!

Guvf vf gur svefg gvzr jr'ir vaivgrq gur Onatnyber Clguba zrrghc pbzzhavgl gb bhe bssvpr, fb rirelbar gnxr n punapr gb argjbex.

Funer lbhe xabjyrqtr, lbhe gvcf naq lbhe rkcregvfr bs Clguba.

Nobir nyy, unir sha!!

Gb bhe ivfvgbef, Ivfn vf uvevat. Ernpu bhg gb hf naq funer lbhe erfhzrf."""

d = {}
for c in (65, 97):
    for i in range(26):
        d[chr(i+c)] = chr((i+13) % 26 + c)

print("".join([d.get(c, c) for c in s]))