寻找从python中的yelp评审数据集构建矩阵的有效方法

Question

目前，我正在寻找一种高效的方法来构建Python中推荐系统的评级矩阵。

矩阵应如下所示：

4|0|0|
5|2|0|
5|0|0|
4|0|0|
4|0|0|
4|0|0|
4|4|0|
2|0|0|
0|4|0|
0|3|0|
0|0|3|
0|0|5|
0|0|4|

具体来说，列是business_id，行是user_id。

      |bus-1|bus-2|
user-1|stars|stars|
user-2|stars|stars|

目前，我正在使用存储在MongoDB中的Yelp数据集：

_id: "----X0BIDP9tA49U3RvdSQ"
user_id: "gVmUR8rqUFdbSeZbsg6z_w"
business_id: "Ue6-WhXvI-_1xUIuapl0zQ"
stars: 4
useful: 1
funny: 0
cool: 0
text: "Red, white and bleu salad was super yum and a great addition to the me..."
date: "2014-02-17 16:48:49"

我的方法是从审查表中构建唯一的business_id和user_id列表，并在复查表中再次查询这些值。

我在这里包含了我的代码，正如您所看到的，由于蛮力方法，构建小矩阵花费了很长时间，就像我前面所包含的那样。

下面是我的代码片段：

def makeBisnisArray(cityNameParam):
    arrayBisnis = []

    #Append business id filtered by cityNameParam to the bisnis array
    bisnisInCity = colBisnis.find({"city": cityNameParam})
    for bisnis in bisnisInCity:
        #if the business id is not in array, then append it to the array
        if(not(bisnis in arrayBisnis)):
            arrayBisnis.append(bisnis["_id"])
    return arrayBisnis

def makeUserArray(bisnisName):
    global arrayUser

    #find review filtered by bisnisName
    hslReview = colReview.find({"business_id": bisnisName})
    for review in hslReview:
        #if the user id is not already in array, append it to the array
        if(not(review['user_id'] in arrayUser)):
            arrayUser.append(review['user_id'])


def writeRatingMatrix(arrayBisnis, arrayUser):
    f = open("file.txt", "w")
    for user in arrayUser:
        for bisnis in arrayBisnis:
            #find one instance from the database by business_id and user_id
            x = colReview.find_one({"business_id": bisnis, "user_id": user})

            #if there's none, then just write the rating as 0
            if x is None :
                f.write('0|')
            #if found, write the star value
            else:
                f.write((str(x['stars'])+"|"))
        print()
        f.write('\n')


def buildCityTable(cityName):
    arrayBisnis = makeBisnisArray(cityName)
    global arrayUser
    for bisnis in arrayBisnis:
        makeUserArray(bisnis)
    writeRatingMatrix(arrayBisnis, arrayUser) 


arrayUser = []
cityNameVar = 'Pointe-Aux-Trembles'
buildCityTable(cityNameVar)

有人能提出更有效的方法为我建立评级矩阵吗？

Answer 1

有几个一般的方法，你可以采取加快这一点。

searches.

• Process

• 使用集合或字典分别建立一组独特的企业和用户；Set/Dict查找要比一次列出yelp文件的速度快得多，一旦

• 使用诸如numpy或熊猫之类的东西来构建矩阵

就像这样

users = {}
businesses = {}
ratings = {}

for entry in yelp_entries:
    if entry['user_id'] not in users:
        users[entry['user_id']] = len(users)
    if entry['business_id'] not in businesses:
        businesses[entry['business_id']] = len(businesses)
    ratings.append((
        users[[entry['user_id']],
        businesses[entry['business_id']],
        entry['stars']
    ))

matrix = numpy.tile(0, (len(users), len(businesses))
for r in ratings:
    matrix[r[0]][r[1]] = r[2]