from .shingle_based import ShingleBased from .string_distance import NormalizedStringDistance from .string_similarity import NormalizedStringSimilarity class SorensenDice(ShingleBased, NormalizedStringDistance, NormalizedStringSimilarity): def __init__(self, k=3): super().__init__(k) def distance(self, s0, s1): return 1.0 - self.similarity(s0, s1) def similarity(self, s0, s1): if s0 is None: raise TypeError("Argument s0 is NoneType.") if s1 is None: raise TypeError("Argument s1 is NoneType.") if s0 == s1: return 1.0 union = set() profile0, profile1 = self.get_profile(s0), self.get_profile(s1) for k in profile0.keys(): union.add(k) for k in profile1.keys(): union.add(k) inter = 0 for k in union: if k in profile0.keys() and k in profile1.keys(): inter += 1 return 2.0 * inter / (len(profile0) + len(profile1))