Brandon <your.mas...@gmail.com> writes: > Thanks bear - > > Some outside advice has me looking at nested dictionaries. But I am > still bogged down because I've not created one before and all examples > I can find are simple ones where they are created manually, not with > loops. Maybe a further example: > > data: > POS1 POS2 POS3 > ['word1','tagA','tagB'] > ['word2','tagC','tagD'] > ['word1','tagE','tagB'] > ['word1','tagC','tagF'] > > ... and so on. FWIW: I am guaranteed that the set of tags that may > occur in position2 is complementary to the set of tags that may occur > in position3. > > Now I want to get an accounting of all the tags that occurred in > position3 in the context of, say, word1. Here I've shown that for > word1, tagB and tagF occurs. I want a way to access all this > information such that nested_dict['word1']['tagB'] = 2, and nested_dict > ['word1']['tagF'] = 1. > > As I mentioned, I already have dicts such that dictA['word1'] = 3, and > dictB['tagB'] = 2. I used defaultdict to build those, and that seems > to be causing me to get some funky values back from my initial > attempts to build a nested dictionary. I am stumbling at constructing > a "for" loop that automatically creates such nested dictionaries. > > I hope that clears things up. If you still have any advice, it's much > appreciated. > > Thanks, > > Brandon
>>> from collections import defaultdict >>> >>> data = [['word1','tagA','tagB'], ... ['word2','tagC','tagD'], ... ['word1','tagE','tagB'], ... ['word1','tagC','tagF']] >>> >>> d = defaultdict(lambda: defaultdict(int)) >>> >>> for w, t1, t2 in data: ... d[w][t2] += 1 ... >>> d['word1']['tagB'] 2 >>> d['word2']['tagD'] 1 >>> d['word2']['tagF'] 0 HTH -- Arnaud -- http://mail.python.org/mailman/listinfo/python-list
