1 #coding=utf-8
  2 import time
  3 class treeNode(object):
  4     """docstring for treeNode"""
  5     def __init__(self, nameValue, numOccur, parentNode):
  6         super(treeNode, self).__init__()
  7         self.name = nameValue
  8         self.count = numOccur
  9         self.nodeLink = None
 10         self.parent = parentNode
 11         self.children = {}
 12     def inc(self, numOccur):
 13         self.count += numOccur
 14     def disp(self, ind=1):
 15         print ‘ ‘*ind,self.name,‘ ‘,self.count
 16         for child in self.children.values():
 17             child.disp(ind+1)
 18 def loadSimpDat():
 19     simpDat = [[‘r‘, ‘z‘, ‘h‘, ‘j‘, ‘p‘],
 20                [‘z‘, ‘y‘, ‘x‘, ‘w‘, ‘v‘, ‘u‘, ‘t‘, ‘s‘],
 21                [‘z‘],
 22                [‘r‘, ‘x‘, ‘n‘, ‘o‘, ‘s‘],
 23                [‘y‘, ‘r‘, ‘x‘, ‘z‘, ‘q‘, ‘t‘, ‘p‘],
 24                [‘y‘, ‘z‘, ‘x‘, ‘e‘, ‘q‘, ‘s‘, ‘t‘, ‘m‘]]
 25     return simpDat
 26 def createInitSet(dataSet):
 27     retDict = {}
 28     for trans in dataSet:
 29         retDict[frozenset(trans)] = 1
 30     return retDict
 31 def createTree(dataSet, minSup=1):
 32     headerTable = {}
 33     #frequency of each item
 34     for trans in dataSet:
 35         for item in trans:
 36             headerTable[item] = headerTable.get(item, 0) + dataSet[trans]#some trans may same
 37     #remove items not meeting minSup
 38     for k in headerTable.keys():
 39         if headerTable[k] < minSup:
 40             del(headerTable[k])
 41     freqItemSet = set(headerTable.keys())
 42     if len(freqItemSet) == 0:#no frequent item
 43         return None, None
 44     for k in headerTable:#add a point field
 45         headerTable[k] = [headerTable[k], None]
 46     
 47     retTree = treeNode(‘Null set‘, 1, None)
 48     for tranSet, count in dataSet.items():
 49         localD = {}
 50         for item in tranSet:#把每一个项集的元素提取出来，并加上统计出来的频率
 51             if item in freqItemSet:
 52                 localD[item] = headerTable[item][0]
 53         if len(localD) > 0:#排序，并更新树
 54             orderdItem = [v[0] for v in sorted(localD.items(),key=lambda p:p[1],reverse=True)]
 55             updateTree(orderdItem, retTree, headerTable, count)
 56     return retTree, headerTable
 57 def updateTree(items, inTree, headerTable, count):
 58     #将新的节点加上来
 59     if items[0] in inTree.children:
 60         inTree.children[items[0]].inc(count)
 61     else:
 62         inTree.children[items[0]] = treeNode(items[0], count, inTree)
 63         #更新指针
 64         if headerTable[items[0]][1] == None:
 65             headerTable[items[0]][1] = inTree.children[items[0]]
 66         else:
 67             updateHeader(headerTable[items[0]][1],inTree.children[items[0]])
 68     if len(items) > 1:
 69         updateTree(items[1::],inTree.children[items[0]],headerTable,count)
 70 def updateHeader(nodeToTest, targetNode):
 71     while nodeToTest.nodeLink != None:
 72         nodeToTest = nodeToTest.nodeLink
 73     nodeToTest.nodeLink = targetNode
 74        
 75 def ascendTree(leafNode, prefixPath): #ascends from leaf node to root
 76     if leafNode.parent != None:
 77         prefixPath.append(leafNode.name)
 78         ascendTree(leafNode.parent, prefixPath)
 79     
 80 def findPrefixPath(basePat, treeNode): #treeNode comes from header table
 81     condPats = {}
 82     while treeNode != None:
 83         prefixPath = []
 84         ascendTree(treeNode, prefixPath)
 85         if len(prefixPath) > 1: 
 86             condPats[frozenset(prefixPath[1:])] = treeNode.count
 87         treeNode = treeNode.nodeLink
 88     return condPats
 89 def mineTree(inTree, headerTable, minSup, preFix, freqItemList):
 90     bigL = [v[0] for v in sorted(headerTable.items(), key=lambda p: p[1])]#(sort header table)
 91     #print bigL
 92     for basePat in bigL:  #start from bottom of header table
 93         newFreqSet = preFix.copy()
 94         newFreqSet.add(basePat)
 95         print ‘finalFrequent Item: ‘,newFreqSet    #append to set
 96         freqItemList.append(newFreqSet)
 97         condPattBases = findPrefixPath(basePat, headerTable[basePat][1])
 98         print ‘condPattBases :‘,basePat, condPattBases
 99         #2. construct cond FP-tree from cond. pattern base
100         myCondTree, myHead = createTree(condPattBases, minSup)
101         print ‘head from conditional tree: ‘, myHead
102         if myHead != None: #3. mine cond. FP-tree
103             print ‘conditional tree for: ‘,newFreqSet
104             myCondTree.disp(1)            
105             mineTree(myCondTree, myHead, minSup, newFreqSet, freqItemList)
106 def main():
107     if True:
108         simpDat = loadSimpDat()
109         initSet = createInitSet(simpDat)
110         myFP, myHeadTable = createTree(initSet,3)
111         myFP.disp()
112         freqItems = []
113         mineTree(myFP,myHeadTable,3,set([]),freqItems)
114         print freqItems
115     if False:
116         t1 = time.clock()
117         parsedDat = [line.split() for line in open(‘kosarak.dat‘).readlines()]
118         initSet = createInitSet(parsedDat)
119         myFP,myHeadTable = createTree(initSet,100000)
120         myfreq = []
121         mineTree(myFP,myHeadTable,100000,set([]),myfreq)
122         t2 = time.clock()
123         print ‘time=‘, t2-t1
124         print myfreq
125 if __name__ == ‘__main__‘:
126     main()
127