Hi! Your attempt solution looks great, but can you think "whats make character last in the word"? And what is the best data structure to implement it?

That's because you decided to rename the function from alphabet_position to transformer2. It won't work, the tests look for the original name.

How are you recreating the tests? How do you know you're using the same regex engine as CW?

I'd recommend coding directly in CW, to make sure it works as it would on CW as you code it.