RosettaCodeData/Task/Levenshtein-distance/Python/levenshtein-distance-2.py

24 lines
699 B
Python

def levenshteinDistance(str1, str2):
m = len(str1)
n = len(str2)
lensum = float(m + n)
d = []
for i in range(m+1):
d.append([i])
del d[0][0]
for j in range(n+1):
d[0].append(j)
for j in range(1,n+1):
for i in range(1,m+1):
if str1[i-1] == str2[j-1]:
d[i].insert(j,d[i-1][j-1])
else:
minimum = min(d[i-1][j]+1, d[i][j-1]+1, d[i-1][j-1]+2)
d[i].insert(j, minimum)
ldist = d[-1][-1]
ratio = (lensum - ldist)/lensum
return {'distance':ldist, 'ratio':ratio}
print(levenshteinDistance("kitten","sitting"))
print(levenshteinDistance("rosettacode","raisethysword"))