Find dictionary items whose key matches a substring

Question

I have a large dictionary constructed like so:

programs[\'New York\'] = \'some values...\' 
programs[\'Port Authority of New York\'] = \'some values...\' 
pr         


        

Answer 1

You should use the brute force method given by mensi until it proves to be too slow.

Here's something that duplicates the data to give a speedier lookup. It only works if your search is for whole words only - i.e. you'll never need to match on "New Yorks Best Bagels" because "york" and "yorks" are different words.

words = {}
for key in programs.keys():
    for w in key.split():
        w = w.lower()
        if w not in words:
            words[w] = set()
        words[w].add(key)


def lookup(search_string, words, programs):
    result_keys = None
    for w in search_string.split():
        w = w.lower()
        if w not in words:
            return []
        result_keys = words[w] if result_keys is None else result_keys.intersection(words[w])
    return [programs[k] for k in result_keys]

If the words have to be in sequence (i.e. "York New" shouldn't match) you can apply the brute-force method to the short list of result_keys.