db.py

import sqlite3
import os.path


def


# use the Lavenshtien similarity index for databases.
def levenshteinDistanceDP(token1, token2):
    distances = numpy.zeros((len(token1) + 1, len(token2) + 1))

    for t1 in range(len(token1) + 1):
        distances[t1][0] = t1

    for t2 in range(len(token2) + 1):
        distances[0][t2] = t2

    a = 0
    b = 0
    c = 0

    for t1 in range(1, len(token1) + 1):
        for t2 in range(1, len(token2) + 1):
            if (token1[t1 - 1] == token2[t2 - 1]):
                distances[t1][t2] = distances[t1 - 1][t2 - 1]
            else:
                a = distances[t1][t2 - 1]
                b = distances[t1 - 1][t2]
                c = distances[t1 - 1][t2 - 1]

                if (a <= b and a <= c):
                    distances[t1][t2] = a + 1
                elif (b <= a and b <= c):
                    distances[t1][t2] = b + 1
                else:
                    distances[t1][t2] = c + 1

    printDistances(distances, len(token1), len(token2))
    return distances[len(token1)][len(token2)]