Help using class methods

[Ofnuts]

To use the class you have to create an instance so you code should have something like:

alphabet=Alphabet()

alphabet['k'] # will call alphabet.__getitem__('k')

Note that nothing says how you initialize the mapping with data, that's up to you. And __getitem__ can just as well compute the answer instead of
looking it up:

import collections
 
class Alphabet(collections.Mapping):
    
    def __len__(self):
       pass

    def __iter__(self):
       pass

    def __getitem__(self,key):
        return ord((key.lower()[0]))-96
   
alphabet=Alphabet()
print (alphabet['a'])
print (alphabet['A'])
print (alphabet['z'])

Btw, using numpy just to read a file is gross.