Event Recommendation Engine Challenge分步解析第三步

import pandas as pd
df_user_friends = pd.read_csv(‘user_friends.csv.gz‘, compression=‘gzip‘)
df_user_friends.head()

from collections import defaultdict
import locale, pycountry
import scipy.sparse as ss
import scipy.io as sio
import itertools
#import cPickle
#From python3, cPickle has beed replaced by _pickle
import _pickle as cPickle

import scipy.spatial.distance as ssd
import datetime
from sklearn.preprocessing import normalize

import gzip
import numpy as np

#处理user和event关联数据
class ProgramEntities:
    """
    我们只关心train和test中出现的user和event，因此重点处理这部分关联数据，
    经过统计：train和test中总共3391个users和13418个events
    """
    def __init__(self):
        #统计训练集中有多少独立的用户的events
        uniqueUsers = set()#uniqueUsers保存总共多少个用户：3391个
        uniqueEvents = set()#uniqueEvents保存总共多少个events：13418个
        eventsForUser = defaultdict(set)#字典eventsForUser保存了每个user:所对应的event
        usersForEvent = defaultdict(set)#字典usersForEvent保存了每个event：哪些user点击
        for filename in [‘train.csv‘, ‘test.csv‘]:
            f = open(filename)
            f.readline()#跳过第一行
            for line in f:
                cols = line.strip().split(‘,‘)
                uniqueUsers.add( cols[0] )
                uniqueEvents.add( cols[1] )
                eventsForUser[cols[0]].add( cols[1] )
                usersForEvent[cols[1]].add( cols[0] )
            f.close()
        
        self.userEventScores = ss.dok_matrix( ( len(uniqueUsers), len(uniqueEvents) ) )
        self.userIndex = dict()
        self.eventIndex = dict()
        for i, u in enumerate(uniqueUsers):
            self.userIndex[u] = i
        for i, e in enumerate(uniqueEvents):
            self.eventIndex[e] = i
            
        ftrain = open(‘train.csv‘)
        ftrain.readline()
        for line in ftrain:
            cols = line.strip().split(‘,‘)
            i = self.userIndex[ cols[0] ]
            j = self.eventIndex[ cols[1] ]
            self.userEventScores[i, j] = int( cols[4] ) - int( cols[5] )
        ftrain.close()
        sio.mmwrite(‘PE_userEventScores‘, self.userEventScores)
        
        #为了防止不必要的计算，我们找出来所有关联的用户或者关联的event
        #所谓关联用户指的是至少在同一个event上有行为的用户user pair
        #关联的event指的是至少同一个user有行为的event pair
        self.uniqueUserPairs = set()
        self.uniqueEventPairs = set()
        for event in uniqueEvents:
            users = usersForEvent[event]
            if len(users) > 2:
                self.uniqueUserPairs.update( itertools.combinations(users, 2) )
        for user in uniqueUsers:
            events = eventsForUser[user]
            if len(events) > 2:
                self.uniqueEventPairs.update( itertools.combinations(events, 2) )
        #rint(self.userIndex)
        cPickle.dump( self.userIndex, open(‘PE_userIndex.pkl‘, ‘wb‘))
        cPickle.dump( self.eventIndex, open(‘PE_eventIndex.pkl‘, ‘wb‘) )
        

#数据清洗类
class DataCleaner:
    def __init__(self):
        #一些字符串转数值的方法
        #载入locale
        self.localeIdMap = defaultdict(int)
        
        for i, l in enumerate(locale.locale_alias.keys()):
            self.localeIdMap[l] = i + 1
            
        #载入country
        self.countryIdMap = defaultdict(int)
        ctryIdx = defaultdict(int)
        for i, c in enumerate(pycountry.countries):
            self.countryIdMap[c.name.lower()] = i + 1
            if c.name.lower() == ‘usa‘:
                ctryIdx[‘US‘] = i
            if c.name.lower() == ‘canada‘:
                ctryIdx[‘CA‘] = i
            
        for cc in ctryIdx.keys():
            for s in pycountry.subdivisions.get(country_code=cc):
                self.countryIdMap[s.name.lower()] = ctryIdx[cc] + 1
                
        self.genderIdMap = defaultdict(int, {‘male‘:1, ‘female‘:2})
                
    #处理LocaleId
    def getLocaleId(self, locstr):
        #这样因为localeIdMap是defaultdict(int)，如果key中没有locstr.lower()，就会返回默认int 0
        return self.localeIdMap[ locstr.lower() ]
        
    #处理birthyear
    def getBirthYearInt(self, birthYear):
        try:
            return 0 if birthYear == ‘None‘ else int(birthYear)
        except:
            return 0
            
    #性别处理
    def getGenderId(self, genderStr):
        return self.genderIdMap[genderStr]
        
    #joinedAt
    def getJoinedYearMonth(self, dateString):
        dttm = datetime.datetime.strptime(dateString, "%Y-%m-%dT%H:%M:%S.%fZ")
        return "".join( [str(dttm.year), str(dttm.month) ] )
        
    #处理location
    def getCountryId(self, location):
        if (isinstance( location, str)) and len(location.strip()) > 0 and location.rfind(‘  ‘) > -1:
            return self.countryIdMap[ location[location.rindex(‘  ‘) + 2: ].lower() ]
        else:
            return 0
                    
    #处理timezone
    def getTimezoneInt(self, timezone):
        try:
            return int(timezone)
        except:
            return 0

#用户与用户相似度矩阵
class Users:
    """
    构建user/user相似度矩阵
    """
    def __init__(self, programEntities, sim=ssd.correlation):#spatial.distance.correlation(u, v) #计算向量u和v之间的相关系数
        cleaner = DataCleaner()
        nusers = len(programEntities.userIndex.keys())#3391
        #print(nusers)
        fin = open(‘users.csv‘)
        colnames = fin.readline().strip().split(‘,‘) #7列特征
        self.userMatrix = ss.dok_matrix( (nusers, len(colnames)-1 ) )#构建稀疏矩阵
        for line in fin:
            cols = line.strip().split(‘,‘)
            #只考虑train.csv中出现的用户，这一行是作者注释上的，但是我不是很理解
            #userIndex包含了train和test的所有用户，为何说只考虑train.csv中出现的用户
            if cols[0] in programEntities.userIndex:
                i = programEntities.userIndex[ cols[0] ]#获取user：对应的index
                self.userMatrix[i, 0] = cleaner.getLocaleId( cols[1] )#locale
                self.userMatrix[i, 1] = cleaner.getBirthYearInt( cols[2] )#birthyear,空值0填充
                self.userMatrix[i, 2] = cleaner.getGenderId( cols[3] )#处理性别
                self.userMatrix[i, 3] = cleaner.getJoinedYearMonth( cols[4] )#处理joinedAt列
                self.userMatrix[i, 4] = cleaner.getCountryId( cols[5] )#处理location
                self.userMatrix[i, 5] = cleaner.getTimezoneInt( cols[6] )#处理timezone
        fin.close()
        
        #归一化矩阵
        self.userMatrix = normalize(self.userMatrix, norm=‘l1‘, axis=0, copy=False)
        sio.mmwrite(‘US_userMatrix‘, self.userMatrix)
        
        #计算用户相似度矩阵，之后会用到
        self.userSimMatrix = ss.dok_matrix( (nusers, nusers) )#(3391,3391)
        for i in range(0, nusers):
            self.userSimMatrix[i, i] = 1.0
        
        for u1, u2 in programEntities.uniqueUserPairs:
            i = programEntities.userIndex[u1]
            j = programEntities.userIndex[u2]
            if (i, j) not in self.userSimMatrix:
                #print(self.userMatrix.getrow(i).todense()) 如[[0.00028123,0.00029847,0.00043592,0.00035208,0,0.00032346]]
                #print(self.userMatrix.getrow(j).todense()) 如[[0.00028123,0.00029742,0.00043592,0.00035208,0,-0.00032346]]
                usim = sim(self.userMatrix.getrow(i).todense(),self.userMatrix.getrow(j).todense())
                self.userSimMatrix[i, j] = usim
                self.userSimMatrix[j, i] = usim
        sio.mmwrite(‘US_userSimMatrix‘, self.userSimMatrix)


#用户社交关系挖掘
class UserFriends:
    """
    找出某用户的那些朋友，想法非常简单
    1）如果你有更多的朋友，可能你性格外向，更容易参加各种活动
    2）如果你朋友会参加某个活动，可能你也会跟随去参加一下
    """
    def __init__(self, programEntities):
        nusers = len(programEntities.userIndex.keys())#3391
        self.numFriends = np.zeros( (nusers) )#array([0., 0., 0., ..., 0., 0., 0.])，保存每一个用户的朋友数
        self.userFriends = ss.dok_matrix( (nusers, nusers) )
        fin = gzip.open(‘user_friends.csv.gz‘)
        print( ‘Header In User_friends.csv.gz:‘,fin.readline() )
        ln = 0
        #逐行打开user_friends.csv.gz文件
        #判断第一列的user是否在userIndex中，只有user在userIndex中才是我们关心的user
        #获取该用户的Index，和朋友数目
        #对于该用户的每一个朋友，如果朋友也在userIndex中，获取其朋友的userIndex，然后去userEventScores中获取该朋友对每个events的反应
        #score即为该朋友对所有events的平均分
        #userFriends矩阵记录了用户和朋友之间的score
        #如851286067：1750用户出现在test.csv中，该用户在User_friends.csv.gz中一共2151个朋友
        #那么其朋友占比应该是2151 / 总的朋友数sumNumFriends=3731377.0 = 2151 / 3731377 = 0.0005764627910822198
        for line in fin:
            if ln % 200 == 0:
                print( ‘Loading line:‘, ln )
            cols = line.decode().strip().split(‘,‘)
            user = cols[0]
            if user in programEntities.userIndex:
                friends = cols[1].split(‘ ‘)#获得该用户的朋友列表
                i = programEntities.userIndex[user]
                self.numFriends[i] = len(friends)
                for friend in friends:
                    if friend in programEntities.userIndex:
                        j = programEntities.userIndex[friend]
                        #the objective of this score is to infer the degree to
                        #and direction in which this friend will influence the
                        #user‘s decision, so we sum the user/event score for
                        #this user across all training events
                        eventsForUser = programEntities.userEventScores.getrow(j).todense()#获取朋友对每个events的反应：0， 1， or -1
                        #print(eventsForUser.sum(), np.shape(eventsForUser)[1] )
                        #socre即是用户朋友在13418个events上的平均分
                        score = eventsForUser.sum() / np.shape(eventsForUser)[1]#eventsForUser = 13418,
                        #print(score)
                        self.userFriends[i, j] += score
                        self.userFriends[j, i] += score
            ln += 1
        fin.close()
        #归一化数组
        sumNumFriends = self.numFriends.sum(axis=0)#每个用户的朋友数相加
        print(sumNumFriends)
        self.numFriends = self.numFriends / sumNumFriends#每个user的朋友数目比例
        sio.mmwrite(‘UF_numFriends‘, np.matrix(self.numFriends) )
        self.userFriends = normalize(self.userFriends, norm=‘l1‘, axis=0, copy=False)
        sio.mmwrite(‘UF_userFriends‘, self.userFriends)
        
print(‘第1步：统计user和event相关信息...‘)
pe = ProgramEntities()
print(‘第1步完成...\n‘)

print(‘第2步：计算用户相似度信息，并用矩阵形式存储...‘)
#Users(pe)
print(‘第2步完成...\n‘)

print(‘第3步：计算用户社交关系信息，并存储...‘)
UserFriends(pe)
print(‘第3步完成...\n‘)