access class attributes using __get*

Question

I have lots of files that are used in tests and I would like to define them in a class, so my editor can resolve it.

class Fixtures:
   file_a = 'file_a.json' 
   file_b = 'file_b.json'    
   file_c = 'file_c.json' 

   def __getattribute__(self, name):
       filename = getattr(Fixtures, name)
       with open(filename, encoding='utf-8') as f:
          return json.load(f, encoding='utf-8') 

Now I can request a file using

Fixtures().file_a  # returns content of file_a.json

However, these are class attributes (not instance attributes), but if I request it as such, __getattribute__ does not get called

Fixtures.file_a  # returns string "file_a.json"

Is there a way to use the attributes as such, without having to instantiate first?