Cracking the BBC's GCHQ Puzzlebook Challenge with Python

Cracking The BBC'S GCHQ Puzzlebook Challenge With Python ...and a wee bit of logical deduction!

As the title suggest, a walkthrough on using some basic Python to aid solving the GCHQ Puzzlebook challenge, as recently published by the BBC.

WARNING: If you fancy attempting the challenge yourself, there are spoilers towards the end of the post.

Pah! I solved it in my head.