I was wondering: would it be possible to access dict values with uncomplete keys (as long as there are not more than one entry for a given string)? For example:
There's a nice and clever implementation of a 'fuzzy' dictionary in pywinauto - this might be perfect for what you need here.
https://code.google.com/p/pywinauto/source/browse/pywinauto/fuzzydict.py
and docs here: http://pywinauto.googlecode.com/hg/pywinauto/docs/code/pywinauto.fuzzydict.html
(edit: although if you specifically want to match from the beginning of the key, you might need to replace SequenceMatcher logic with your custom code)