help on dictionary

[cesco]

Hi,

I have a defaultdict which I have initialized as follows:

def train(features):
    model = collections.defaultdict(lambda: 1)
    for f in features:
        model[f] += 1
    return model

def_dict = train(large_set_of_words)

where large_set_of_words is the list of possible strings.

I'd like to use such a default_dict as follows:

return max(list_of_strings, key=lambda w: dic[w])

that is, among the strings in list_of_strings, I'd like to return the
one with the highest score in def_dict.

The problem with such approach is that if the list_of_strings contains
a string that is not part of the def_dict, such a string gets added to
it while I'd like to keep the original def_dict unchanged/frozen.

Do you have any suggestion on how to do that?

Thanks and regards
Francesco

P.S. the code above is part from Norvig's spelling corrector