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  • 机器学习12—FP-growth学习笔记

    test12.py

    #-*- coding:utf-8
    import sys
    sys.path.append("fpGrowth.py")
    
    import fpGrowth
    from numpy import *
    
    # rootNode = fpGrowth.treeNode('pyramid', 9, None)
    # rootNode.children['eye'] = fpGrowth.treeNode('eye', 13, None)
    
    # rootNode.children['phoenix'] = fpGrowth.treeNode('phoenix', 3, None)
    # rootNode.disp()
    
    
    
    simpDat = fpGrowth.loadSimpDat()
    # print(simpDat)
    
    initSet = fpGrowth.createInitSet(simpDat)
    # print(initSet)
    
    
    myFPtree, myHeaderTab = fpGrowth.createTree(initSet, 3)
    # myFPtree.disp()
    
    # resX = fpGrowth.findPrefixPath('x', myHeaderTab['x'][1])
    # print(resX)
    # resZ = fpGrowth.findPrefixPath('z', myHeaderTab['z'][1])
    # print(resZ)
    # resR = fpGrowth.findPrefixPath('r', myHeaderTab['r'][1])
    # print(resR)
    
    freqItems = []
    fpGrowth.mineTree(myFPtree, myHeaderTab, 3, set([]), freqItems)
    
    
    print("freqItems:")
    print(freqItems)
    
    
    print("over!!!")
    fpGrowth.py
    '''
    Created on Jun 14, 2011
    FP-Growth FP means frequent pattern
    the FP-Growth algorithm needs: 
    1. FP-tree (class treeNode)
    2. header table (use dict)
    
    This finds frequent itemsets similar to apriori but does not 
    find association rules.  
    
    @author: Peter
    '''
    class treeNode:
        def __init__(self, nameValue, numOccur, parentNode):
            self.name = nameValue
            self.count = numOccur
            self.nodeLink = None
            self.parent = parentNode      #needs to be updated
            self.children = {} 
        
        def inc(self, numOccur):
            self.count += numOccur
            
        def disp(self, ind=1):
            print('  '*ind, self.name, ' ', self.count)
            for child in self.children.values():
                child.disp(ind+1)
    
    def createTree(dataSet, minSup=1): #create FP-tree from dataset but don't mine
        headerTable = {}
        #go over dataSet twice
        for trans in dataSet:#first pass counts frequency of occurance
            for item in trans:
                # test0 = headerTable.get(item, 0)
                # test1 = dataSet[trans]
                headerTable[item] = headerTable.get(item, 0) + dataSet[trans]
        for k in list(headerTable):  #remove items not meeting minSup
            if headerTable[k] < minSup:
                del(headerTable[k])
        freqItemSet = set(headerTable.keys())
        #print 'freqItemSet: ',freqItemSet
        if len(freqItemSet) == 0: return None, None  #if no items meet min support -->get out
        for k in headerTable:
            headerTable[k] = [headerTable[k], None] #reformat headerTable to use Node link
        #print('headerTable: ',headerTable)
        retTree = treeNode('Null Set', 1, None) #create tree
        for tranSet, count in dataSet.items():     #go through dataset 2nd time
            localD = {}
            for item in tranSet:  #put transaction items in order
                if item in freqItemSet:
                    localD[item] = headerTable[item][0]
            if len(localD) > 0:
                orderedItems = [v[0] for v in sorted(localD.items(), key=lambda p: p[1], reverse=True)]
                updateTree(orderedItems, retTree, headerTable, count)#populate tree with ordered freq itemset
        return retTree, headerTable #return tree and header table
    
    def updateTree(items, inTree, headerTable, count):
        if items[0] in inTree.children:#check if orderedItems[0] in retTree.children
            inTree.children[items[0]].inc(count) #incrament count
        else:   #add items[0] to inTree.children
            inTree.children[items[0]] = treeNode(items[0], count, inTree)
            if headerTable[items[0]][1] == None: #update header table
                headerTable[items[0]][1] = inTree.children[items[0]]
            else:
                updateHeader(headerTable[items[0]][1], inTree.children[items[0]])
        if len(items) > 1:#call updateTree() with remaining ordered items
            updateTree(items[1::], inTree.children[items[0]], headerTable, count)
    
    def updateHeader(nodeToTest, targetNode):   #this version does not use recursion
        while (nodeToTest.nodeLink != None):    #Do not use recursion to traverse a linked list!
            nodeToTest = nodeToTest.nodeLink
        nodeToTest.nodeLink = targetNode
    
    def ascendTree(leafNode, prefixPath): #ascends from leaf node to root
        if leafNode.parent != None:
            prefixPath.append(leafNode.name)
            ascendTree(leafNode.parent, prefixPath)
    
    def findPrefixPath(basePat, treeNode): #treeNode comes from header table
        condPats = {}
        while treeNode != None:
            prefixPath = []
            ascendTree(treeNode, prefixPath)
            if len(prefixPath) > 1:
                condPats[frozenset(prefixPath[1:])] = treeNode.count
            treeNode = treeNode.nodeLink
        return condPats
    
    def mineTree(inTree, headerTable, minSup, preFix, freqItemList):
        bigL = [v[0] for v in sorted(headerTable.items(), key=lambda p: p[1][0])]#(sort header table)
        for basePat in bigL:  #start from bottom of header table
            newFreqSet = preFix.copy()
            newFreqSet.add(basePat)
            #print('finalFrequent Item: ',newFreqSet)    #append to set
            freqItemList.append(newFreqSet)
            condPattBases = findPrefixPath(basePat, headerTable[basePat][1])
            #print('condPattBases :',basePat, condPattBases)
            #2. construct cond FP-tree from cond. pattern base
            myCondTree, myHead = createTree(condPattBases, minSup)
            #print('head from conditional tree: ', myHead)
            if myHead != None: #3. mine cond. FP-tree
                print('conditional tree for: ',newFreqSet)
                myCondTree.disp(1)
                mineTree(myCondTree, myHead, minSup, newFreqSet, freqItemList)
    
    def loadSimpDat():
        simpDat = [['r', 'z', 'h', 'j', 'p'],
                   ['z', 'y', 'x', 'w', 'v', 'u', 't', 's'],
                   ['z'],
                   ['r', 'x', 'n', 'o', 's'],
                   ['y', 'r', 'x', 'z', 'q', 't', 'p'],
                   ['y', 'z', 'x', 'e', 'q', 's', 't', 'm']]
        return simpDat
    
    def createInitSet(dataSet):
        retDict = {}
        for trans in dataSet:
            retDict[frozenset(trans)] = 1
        return retDict
    
    import twitter
    from time import sleep
    import re
    
    def textParse(bigString):
        urlsRemoved = re.sub('(http:[/][/]|www.)([a-z]|[A-Z]|[0-9]|[/.]|[~])*', '', bigString)
        listOfTokens = re.split(r'W*', urlsRemoved)
        return [tok.lower() for tok in listOfTokens if len(tok) > 2]
    
    def getLotsOfTweets(searchStr):
        CONSUMER_KEY = ''
        CONSUMER_SECRET = ''
        ACCESS_TOKEN_KEY = ''
        ACCESS_TOKEN_SECRET = ''
        api = twitter.Api(consumer_key=CONSUMER_KEY, consumer_secret=CONSUMER_SECRET,
                          access_token_key=ACCESS_TOKEN_KEY,
                          access_token_secret=ACCESS_TOKEN_SECRET)
        #you can get 1500 results 15 pages * 100 per page
        resultsPages = []
        for i in range(1,15):
            print("fetching page %d" % i)
            searchResults = api.GetSearch(searchStr, per_page=100, page=i)
            resultsPages.append(searchResults)
            sleep(6)
        return resultsPages
    
    def mineTweets(tweetArr, minSup=5):
        parsedList = []
        for i in range(14):
            for j in range(100):
                parsedList.append(textParse(tweetArr[i][j].text))
        initSet = createInitSet(parsedList)
        myFPtree, myHeaderTab = createTree(initSet, minSup)
        myFreqList = []
        mineTree(myFPtree, myHeaderTab, minSup, set([]), myFreqList)
        return myFreqList
    
    #minSup = 3
    #simpDat = loadSimpDat()
    #initSet = createInitSet(simpDat)
    #myFPtree, myHeaderTab = createTree(initSet, minSup)
    #myFPtree.disp()
    #myFreqList = []
    #mineTree(myFPtree, myHeaderTab, minSup, set([]), myFreqList)
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  • 原文地址:https://www.cnblogs.com/Vae1990Silence/p/8631576.html
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