How to turn a defaultdict into a normal dict.

[Antoon Pardon]

The problem I face is that at the building face, I need a defaultdict 
because the values are lists that are appended too. So a 
defaultdict(list) is convenient in that new entries are treated as if
the value is an empty list.

However later when I actually use it, accessing a key that is not 
present, should raise KeyError.

Is that somehow possible?

-- 
Antoon Pardon.