longest prefix match

longest_match_datrie.py

import string
import datrie # pip install datrie

def longest_match_datrie(search, hosts):
    trie = datrie.new(alphabet=string.printable)
    for url in hosts:
        trie[url.decode('ascii')] = 1

    matches = trie.keys(search.decode('ascii'))
    return max(matches, key=len) if matches else ''

print longest_match_datrie("ab", ["ab", "abc", "cab", "cba",
                                  "cabd", "cdab", "acbd", "bcad"])
# -> abc