酒店推荐系统（基于文本描述）

基于酒店文本描述来推荐相似酒店

针对新用户可以通过该用户搜索酒店的关键词进行推荐

import pandas as pd
import numpy as np
from nltk.corpus import stopwords
from sklearn.metrics.pairwise import linear_kernel
from sklearn.feature_extraction.text import CountVectorizer
from sklearn.feature_extraction.text import TfidfVectorizer
import re
import random
import cufflinks
from plotly.offline import iplot
cufflinks.go_offline()

查看酒店的详细数据
名字，位置，详细介绍等

df = pd.read_csv('Seattle_Hotels.csv', encoding="latin-1")
df.head()

查看数据集中酒店的文本描述信息

vec = CountVectorizer().fit(df['desc'])
bag_of_words = vec.transform(df['desc'])

通过计词器查看文本大小（一共152句话，3200个词）
因为数据集中共152条

bag_of_words.shape

查看词出现的个数

sum_words = bag_of_words.sum(axis=0)
sum_words

查看词出现次数
从第一个词开始进行遍历

words_freq = [(word,sum_words[0,idx]) for word,idx in vec.vocabulary_.items()]
words_freq

把词出现的次数进行排序（从大到小）

words_freq = sorted(words_freq,key=lambda x:x[1],reverse=True)
words_freq

集中处理，合并为一个函数

def get_top_n_words(corpus,n=None):
    vec = CountVectorizer().fit(corpus)
    bag_of_words = vec.transform(corpus)
    sum_words = bag_of_words.sum(axis=0)
    words_freq = [(word,sum_words[0,idx]) for word,idx in vec.vocabulary_.items()]
    words_freq = sorted(words_freq,key=lambda x:x[1],reverse=True)
    return words_freq[:n]

common_words=get_top_n_words(df['desc'],20)

common_words

转化一下格式

df1 = pd.DataFrame(common_words,columns=['desc','count'])

画图展示，利用词和词频

df1.groupby('desc').sum()['count'].sort_values().iplot(kind='barh',yTitle='Count',linecolor='black',title='top 20 before remove stopwords')

def get_top_n_words(corpus,n=None):
    vec = CountVectorizer(stop_words='english').fit(corpus)
    bag_of_words = vec.transform(corpus)
    sum_words = bag_of_words.sum(axis=0)
    words_freq = [(word,sum_words[0,idx]) for word,idx in vec.vocabulary_.items()]
    words_freq = sorted(words_freq,key=lambda x:x[1],reverse=True)
    return words_freq[:n]

找出key_words

common_words=get_top_n_words(df['desc'],20)
df2 = pd.DataFrame(common_words,columns=['desc','count'])
df2.groupby('desc').sum()['count'].sort_values().iplot(kind='barh',yTitle='Count',linecolor='black',title='top 20 after remove stopwords')

可以看出处理之后和处理之前的区别（过滤掉一些无用词）

把词进行匹配，上述统计过程中词均是单个的没法完成推荐，要匹配到一起才有意义，以为搜索时也不可能利用一个词来搜索比如要把停车和场要匹配

def get_top_n_words(corpus,n=None):
    vec = CountVectorizer(stop_words='english',ngram_range=(1,3)).fit(corpus)
    bag_of_words = vec.transform(corpus)
    sum_words = bag_of_words.sum(axis=0)
    words_freq = [(word,sum_words[0,idx]) for word,idx in vec.vocabulary_.items()]
    words_freq = sorted(words_freq,key=lambda x:x[1],reverse=True)
    return words_freq[:n]

common_words=get_top_n_words(df['desc'],20)
df3 = pd.DataFrame(common_words,columns=['desc','count'])
df3.groupby('desc').sum()['count'].sort_values().iplot(kind='barh',yTitle='Count',linecolor='black',title='top 20 before remove stopwords-ngram_range=(2,2)')

描述的一些统计信息

df['word_count']=df['desc'].apply(lambda x:len(str(x).split()))

df.head()

查看酒店描述时每句话出现词的个数的分布

df['word_count'].iplot(kind='hist',bins=50)

文本处理
利用正则。来保留自己需要的数据，过滤不需要的数据
转化大小写和替换，利用工具包
替换时如果不在提供此词表中就拿过来，并进行拼接

sub_replace = re.compile('[^0-9a-z #+_]')
stopwords = set(stopwords.words('english'))

def clean_txt(text):
    text.lower()
    text = sub_replace.sub('',text)
    ' '.join(word for word in text.split() if word not in stopwords)
    return text
df['desc_clean'] = df['desc'].apply(clean_txt)

查看结果

df.head()

查看对比，人工加入提供词表越多效果越好

df['desc'][0]

df['desc_clean'][0]

计算相似度（余弦相似度）

df.set_index('name',inplace = True)

tf=TfidfVectorizer(analyzer='word',ngram_range=(1,3),stop_words='english')

转化

tfidf_matrix=tf.fit_transform(df['desc_clean'])

计算余弦相似度，把文本转化成数值方便计算相似度

cosine_similarity =linear_kernel(tfidf_matrix,tfidf_matrix)

查看第一个数据的相似度

cosine_similarity[0]

自己与自己相似度为1

构造一个索引

indices = pd.Series(df.index)
indices[:5]

定义一个函数，做相似度推荐

def recommendations(name,cosine_similarity):
    recommended_hotels = []
    idx = indices[indices == name].index[0]
    score_series = pd.Series(cosine_similarity[idx]).sort_values(ascending=False)
    top_10_indexes = list(score_series[1:11].index)
    for i in top_10_indexes:
        recommended_hotels.append(list(df.index)[i])
    return recommended_hotels

得出推荐结果

recommendations('Hilton Garden Seattle Downtown',cosine_similarity)