/+junk/pygooglechart-py3k

class CountryCodes:

    '''

    This is just a helper to generate useful data files. It isn't directly used

    in these examples.

    '''

    def __init__(self):

        self.parse_codes_data()   

    def parse_codes_data(self):

        lines = open('iso3166-1-a2.txt', 'rb').read().split('\n')

        self.codes = dict([ a.split(' ', 1) for a in lines[:-1] ])

    def get_country_code_from_name(self, guess_name):

        best_score = 100

        best_code = None

        for code, name in self.codes.items():

            score = self.levenshtein(guess_name, name)

            if score < best_score:

                best_score = score

                best_code = code

        return best_code

    def levenshtein(self, a, b):

        "Calculates the Levenshtein distance between a and b."

        n, m = len(a), len(b)

        if n > m:

            # Make sure n <= m, to use O(min(n,m)) space

            a,b = b,a

            n,m = m,n

        current = range(n+1)

        for i in range(1,m+1):

            previous, current = current, [i]+[0]*n

            for j in range(1,n+1):

                add, delete = previous[j]+1, current[j-1]+1

                change = previous[j-1]

                if a[j-1] != b[i-1]:

                    change = change + 1

                current[j] = min(add, delete, change)

        return current[n]