Merging Clusters.py

# Enter code for the ClusterSet class in this box
class ClusterSet(object):
    """ A ClusterSet is defined as a list of clusters """
    def __init__(self, pointType):
        """ Initialize an empty set, without any clusters """
        self.members = []
    def add(self, c):
        """ Append a cluster to the end of the cluster list
        only if it doesn't already exist. If it is already in the 
        cluster set, raise a ValueError """
        if c in self.members:
            raise ValueError
        self.members.append(c)
    def getClusters(self):
        return self.members[:]
    def mergeClusters(self, c1, c2):
        points = []
        for p in c1.members():
            points.append(p)
        for p in c2.members():
            points.append(p)
        newC = Cluster(points, type(p))
        self.members.remove(c1)
        self.members.remove(c2)
        self.add(newC)
        return c1, c2
    def findClosest(self, metric):
        minDistance = metric(self.members[0], self.members[1])
        toMerge = (self.members[0], self.members[1])
        for c1 in self.members:
            for c2 in self.members:
                if c1 == c2:
                    continue
                if metric(c1, c2) < minDistance:
                    minDistance = metric(c1, c2)
                    toMerge = (c1, c2)
        return toMerge    
    def mergeOne(self, metric, toPrint = False):
        if len(self.members) == 1:
            return None
        if len(self.members) == 2:
            return self.mergeClusters(self.members[0],
                                      self.members[1])
        toMerge = self.findClosest(metric)
        if toPrint:
            print 'Merged'
            print '  ' + str(toMerge[0])
            print 'with'
            print '  ' + str(toMerge[1])
        self.mergeClusters(toMerge[0], toMerge[1])
        return toMerge
    def numClusters(self):
        return len(self.members)
    def toStr(self):
        cNames = []
        for c in self.members:
            cNames.append(c.getNames())
        cNames.sort()
        result = ''
        for i in range(len(cNames)):
            names = ''
            for n in cNames[i]:
                names += n + ', '
            names = names[:-2]
            result += '  C' + str(i) + ':' + names + '\n'
        return result