That is a lot of typing, while holding the shift key. Python treats a string as an iterable. We can traverse one just as easily as a list (or tuple). Using the the unpacking tool, (*) we can create a list from a string.
letters = [*'abcdefghijklmnopqrstuvwxyz']
We still end up with two lists in memory, the letters and the points. That on top of the dictionary we created from them. What if we put everything right inside the dict comprehension? The lists will evaporate and leave no memory footprint.