My XOR-Decryption algorithm doesn't work.

Question

Here is a problem I've come across on Project Euler some time ago. I wasn't able to solve it then and I still fail to see what is wrong with my code - that's why I'm posting it here now, hoping to be enlightened.

It is about XOR-Encryption. The task is to decrypt a given file. Have a look at their website for a complete problem description.

https://projecteuler.net/problem=59

https://code.sololearn.com/c30pLI9R1Jr8/?ref=app

Answer 1

The code isn't giving any error. What's the problem are you facing?

Answer 2

@Shashi Ranjan
I expect it to print the right key and the decrypted plain text, but apparently it iterates over all the possible key combinations (aaa upto zzz) without finding anything resembling readable English.
The lone number it prints is only the iteration count, not the solution.