def distance(self, gene1, gene2):
    if ((type(gene1) != str) or (type(gene2) != str)):
        return 'Genes have to be strings'
    if (len(gene1) != len(gene2)):
        return 'Genes have to have same lenghts'
    diff = 0
    for i in range(0, len(gene1)):
        if (gene1[i] != gene2[i]):
            diff += 1
    return diff
def distance(self, gene1, gene2):
    if ((type(gene1) != str) or (type(gene2) != str)):
        return 'Genes have to be strings'
    if (len(gene1) != len(gene2)):
        return 'Genes have to have same lenghts'
    diff = 0
    for i in range(0, len(gene1)):
        if (gene1[i] != gene2[i]):
            diff += 1
    return diff