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github上一个开源的简单的推荐系统,使用TensorFlow2和Python 3开发。
使用文本卷积神经网络,并利用MovieLens数据集完成电影推荐的任务。 实现的推荐功能如下:
1、指定用户和电影进行评分
2、推荐同类型的电影
3、推荐您喜欢的电影
4、看过这个电影的人还看了(喜欢)哪些电影
将网络模型作为回归问题进行训练,得到训练好的用户特征矩阵和电影特征矩阵进行推荐,模型结构图:
源代码:
import tensorflow as tf from sklearn.model_selection import train_test_split import numpy as np from collections import Counter import pandas as pd import matplotlib.pyplot as plt import os import pickle import re from tensorflow.python.ops import math_ops import datetime from tensorflow import keras from tensorflow.python.ops import summary_ops_v2 import time import random print(tf.__version__) # 用户数据 # 分别有用户ID、性别、年龄、职业ID和邮编等字段。 # 数据中的格式:UserID::Gender::Age::Occupation::Zip-code # Gender is denoted by a "M" for male and "F" for female # # Age is chosen from the following ranges: # # 1: "Under 18" # 18: "18-24" # 25: "25-34" # 35: "35-44" # 45: "45-49" # 50: "50-55" # 56: "56+" # Occupation is chosen from the following choices: # # 0: "other" or not specified # 1: "academic/educator" # 2: "artist" # 3: "clerical/admin" # 4: "college/grad student" # 5: "customer service" # 6: "doctor/health care" # 7: "executive/managerial" # 8: "farmer" # 9: "homemaker" # 10: "K-12 student" # 11: "lawyer" # 12: "programmer" # 13: "retired" # 14: "sales/marketing" # 15: "scientist" # 16: "self-employed" # 17: "technician/engineer" # 18: "tradesman/craftsman" # 19: "unemployed" # 20: "writer" users_title = ['UserID', 'Gender', 'Age', 'OccupationID', 'Zip-code'] users = pd.read_csv('./ml-1m/users.dat', sep='::', header=None, names=users_title, engine = 'python') # 可以看出UserID、Gender、Age和Occupation都是类别字段,其中邮编字段是我们不使用的 print(users.head()) # 电影数据 # 分别有电影ID、电影名和电影风格等字段。 # 数据中的格式:MovieID::Title::Genres # # Titles are identical to titles provided by the IMDB (including year of release) # # Genres are pipe-separated and are selected from the following genres: # # Action # Adventure # Animation # Children's # Comedy # Crime # Documentary # Drama # Fantasy # Film-Noir # Horror # Musical # Mystery # Romance # Sci-Fi # Thriller # War # Western movies_title = ['MovieID', 'Title', 'Genres'] movies = pd.read_csv('./ml-1m/movies.dat', sep='::', header=None, names=movies_title, engine = 'python') # MovieID是类别字段,Title是文本,Genres也是类别字段 print(movies.head()) # 评分数据 # 分别有用户ID、电影ID、评分和时间戳等字段。 # 数据中的格式:UserID::MovieID::Rating::Timestamp # # UserIDs range between 1 and 6040 # MovieIDs range between 1 and 3952 # Ratings are made on a 5-star scale (whole-star ratings only) # Timestamp is represented in seconds since the epoch as returned by time(2) # Each user has at least 20 ratings ratings_title = ['UserID','MovieID', 'Rating', 'timestamps'] ratings = pd.read_csv('./ml-1m/ratings.dat', sep='::', header=None, names=ratings_title, engine = 'python') # 评分字段Rating就是我们要学习的targets,时间戳字段我们不使用。 print(ratings.head()) # 数据预处理 # UserID、Occupation和MovieID不用变。 # Gender字段:需要将‘F’和‘M’转换成0和1。 # Age字段:要转成7个连续数字0~6。 # Genres字段:是分类字段,要转成数字。首先将Genres中的类别转成字符串到数字的字典,然后再将每个电影的Genres字段转成数字列表,因为有些电影是多个Genres的组合。 # Title字段:处理方式跟Genres字段一样,首先创建文本到数字的字典,然后将Title中的描述转成数字的列表。另外Title中的年份也需要去掉。 # Genres和Title字段需要将长度统一,这样在神经网络中方便处理。空白部分用‘< PAD >’对应的数字填充。 def load_data(): """ Load Dataset from File """ # 读取User数据 users_title = ['UserID', 'Gender', 'Age', 'JobID', 'Zip-code'] users = pd.read_csv('./ml-1m/users.dat', sep='::', header=None, names=users_title, engine='python') users = users.filter(regex='UserID|Gender|Age|JobID') users_orig = users.values # 改变User数据中性别和年龄 gender_map = {'F': 0, 'M': 1} users['Gender'] = users['Gender'].map(gender_map) age_map = {val: ii for ii, val in enumerate(set(users['Age']))} users['Age'] = users['Age'].map(age_map) # 读取Movie数据集 movies_title = ['MovieID', 'Title', 'Genres'] movies = pd.read_csv('./ml-1m/movies.dat', sep='::', header=None, names=movies_title, engine='python') movies_orig = movies.values # 将Title中的年份去掉 pattern = re.compile(r'^(.*)\((\d+)\)$') title_map = {val: pattern.match(val).group(1) for ii, val in enumerate(set(movies['Title']))} movies['Title'] = movies['Title'].map(title_map) # 电影类型转数字字典 genres_set = set() for val in movies['Genres'].str.split('|'): genres_set.update(val) genres_set.add('<PAD>') genres2int = {val: ii for ii, val in enumerate(genres_set)} # 将电影类型转成等长数字列表,长度是18 genres_map = {val: [genres2int[row] for row in val.split('|')] for ii, val in enumerate(set(movies['Genres']))} for key in genres_map: for cnt in range(max(genres2int.values()) - len(genres_map[key])): genres_map[key].insert(len(genres_map[key]) + cnt, genres2int['<PAD>']) movies['Genres'] = movies['Genres'].map(genres_map) # 电影Title转数字字典 title_set = set() for val in movies['Title'].str.split(): title_set.update(val) title_set.add('<PAD>') title2int = {val: ii for ii, val in enumerate(title_set)} # 将电影Title转成等长数字列表,长度是15 title_count = 15 title_map = {val: [title2int[row] for row in val.split()] for ii, val in enumerate(set(movies['Title']))} for key in title_map: for cnt in range(title_count - len(title_map[key])): title_map[key].insert(len(title_map[key]) + cnt, title2int['<PAD>']) movies['Title'] = movies['Title'].map(title_map) # 读取评分数据集 ratings_title = ['UserID', 'MovieID', 'ratings', 'timestamps'] ratings = pd.read_csv('./ml-1m/ratings.dat', sep='::', header=None, names=ratings_title, engine='python') ratings = ratings.filter(regex='UserID|MovieID|ratings') # 合并三个表 data = pd.merge(pd.merge(ratings, users), movies) # 将数据分成X和y两张表 target_fields = ['ratings'] features_pd, targets_pd = data.drop(target_fields, axis=1), data[target_fields] features = features_pd.values targets_values = targets_pd.values return title_count, title_set, genres2int, features, targets_values, ratings, users, movies, data, movies_orig, users_orig # 加载数据并保存到本地 # title_count:Title字段的长度(15) # title_set:Title文本的集合 # genres2int:电影类型转数字的字典 # features:是输入X # targets_values:是学习目标y # ratings:评分数据集的Pandas对象 # users:用户数据集的Pandas对象 # movies:电影数据的Pandas对象 # data:三个数据集组合在一起的Pandas对象 # movies_orig:没有做数据处理的原始电影数据 # users_orig:没有做数据处理的原始用户数据 title_count, title_set, genres2int, features, targets_values, ratings, users, movies, data, movies_orig, users_orig = load_data() pickle.dump((title_count, title_set, genres2int, features, targets_values, ratings, users, movies, data, movies_orig, users_orig), open('preprocess_data.p', 'wb')) # 预处理后的数据 print(users) print(movies) print(ratings) print(features) print(movies.values[0]) # 从本地读取数据 title_count, title_set, genres2int, features, targets_values, ratings, users, movies, data, movies_orig, users_orig = pickle.load(open('preprocess_data.p', mode='rb')) # 辅助函数 def save_params(params): """ Save parameters to file """ pickle.dump(params, open('params.p', 'wb')) def load_params(): """ Load parameters from file """ return pickle.load(open('params.p', mode='rb')) # 编码实现 # 参数 #嵌入矩阵的维度 embed_dim = 32 #用户ID个数 uid_max = max(features.take(0,1)) + 1 # 6040 #性别个数 gender_max = max(features.take(2,1)) + 1 # 1 + 1 = 2 #年龄类别个数 age_max = max(features.take(3,1)) + 1 # 6 + 1 = 7 #职业个数 job_max = max(features.take(4,1)) + 1# 20 + 1 = 21 #电影ID个数 movie_id_max = max(features.take(1,1)) + 1 # 3952 #电影类型个数 movie_categories_max = max(genres2int.values()) + 1 # 18 + 1 = 19 #电影名单词个数 movie_title_max = len(title_set) # 5216 #对电影类型嵌入向量做加和操作的标志,考虑过使用mean做平均,但是没实现mean combiner = "sum" #电影名长度 sentences_size = title_count # = 15 #文本卷积滑动窗口,分别滑动2, 3, 4, 5个单词 window_sizes = {2, 3, 4, 5} #文本卷积核数量 filter_num = 8 #电影ID转下标的字典,数据集中电影ID跟下标不一致,比如第5行的数据电影ID不一定是5 movieid2idx = {val[0]:i for i, val in enumerate(movies.values)} # 超参 # Number of Epochs num_epochs = 5 # Batch Size batch_size = 256 dropout_keep = 0.5 # Learning Rate learning_rate = 0.0001 # Show stats for every n number of batches show_every_n_batches = 20 save_dir = './save' # 输入 # 定义输入的占位符 def get_inputs(): uid = tf.keras.layers.Input(shape=(1,), dtype='int32', name='uid') user_gender = tf.keras.layers.Input(shape=(1,), dtype='int32', name='user_gender') user_age = tf.keras.layers.Input(shape=(1,), dtype='int32', name='user_age') user_job = tf.keras.layers.Input(shape=(1,), dtype='int32', name='user_job') movie_id = tf.keras.layers.Input(shape=(1,), dtype='int32', name='movie_id') movie_categories = tf.keras.layers.Input(shape=(18,), dtype='int32', name='movie_categories') movie_titles = tf.keras.layers.Input(shape=(15,), dtype='int32', name='movie_titles') return uid, user_gender, user_age, user_job, movie_id, movie_categories, movie_titles # 构建神经网络 # 定义User的嵌入矩阵 def get_user_embedding(uid, user_gender, user_age, user_job): uid_embed_layer = tf.keras.layers.Embedding(uid_max, embed_dim, input_length=1, name='uid_embed_layer')(uid) gender_embed_layer = tf.keras.layers.Embedding(gender_max, embed_dim // 2, input_length=1, name='gender_embed_layer')(user_gender) age_embed_layer = tf.keras.layers.Embedding(age_max, embed_dim // 2, input_length=1, name='age_embed_layer')(user_age) job_embed_layer = tf.keras.layers.Embedding(job_max, embed_dim // 2, input_length=1, name='job_embed_layer')(user_job) return uid_embed_layer, gender_embed_layer, age_embed_layer, job_embed_layer # 将User的嵌入矩阵一起全连接生成User的特征 def get_user_feature_layer(uid_embed_layer, gender_embed_layer, age_embed_layer, job_embed_layer): #第一层全连接 uid_fc_layer = tf.keras.layers.Dense(embed_dim, name="uid_fc_layer", activation='relu')(uid_embed_layer) gender_fc_layer = tf.keras.layers.Dense(embed_dim, name="gender_fc_layer", activation='relu')(gender_embed_layer) age_fc_layer = tf.keras.layers.Dense(embed_dim, name="age_fc_layer", activation='relu')(age_embed_layer) job_fc_layer = tf.keras.layers.Dense(embed_dim, name="job_fc_layer", activation='relu')(job_embed_layer) #第二层全连接 user_combine_layer = tf.keras.layers.concatenate([uid_fc_layer, gender_fc_layer, age_fc_layer, job_fc_layer], 2) #(?, 1, 128) user_combine_layer = tf.keras.layers.Dense(200, activation='tanh')(user_combine_layer) #(?, 1, 200) user_combine_layer_flat = tf.keras.layers.Reshape([200], name="user_combine_layer_flat")(user_combine_layer) return user_combine_layer, user_combine_layer_flat # 定义Movie ID的嵌入矩阵 def get_movie_id_embed_layer(movie_id): movie_id_embed_layer = tf.keras.layers.Embedding(movie_id_max, embed_dim, input_length=1, name='movie_id_embed_layer')(movie_id) return movie_id_embed_layer # 合并电影类型的多个嵌入向量 def get_movie_categories_layers(movie_categories): movie_categories_embed_layer = tf.keras.layers.Embedding(movie_categories_max, embed_dim, input_length=18, name='movie_categories_embed_layer')(movie_categories) movie_categories_embed_layer = tf.keras.layers.Lambda(lambda layer: tf.reduce_sum(layer, axis=1, keepdims=True))(movie_categories_embed_layer) # movie_categories_embed_layer = tf.keras.layers.Reshape([1, 18 * embed_dim])(movie_categories_embed_layer) return movie_categories_embed_layer # Movie Title的文本卷积网络实现 def get_movie_cnn_layer(movie_titles): #从嵌入矩阵中得到电影名对应的各个单词的嵌入向量 movie_title_embed_layer = tf.keras.layers.Embedding(movie_title_max, embed_dim, input_length=15, name='movie_title_embed_layer')(movie_titles) sp=movie_title_embed_layer.shape movie_title_embed_layer_expand = tf.keras.layers.Reshape([sp[1], sp[2], 1])(movie_title_embed_layer) #对文本嵌入层使用不同尺寸的卷积核做卷积和最大池化 pool_layer_lst = [] for window_size in window_sizes: conv_layer = tf.keras.layers.Conv2D(filter_num, (window_size, embed_dim), 1, activation='relu')(movie_title_embed_layer_expand) maxpool_layer = tf.keras.layers.MaxPooling2D(pool_size=(sentences_size - window_size + 1 ,1), strides=1)(conv_layer) pool_layer_lst.append(maxpool_layer) #Dropout层 pool_layer = tf.keras.layers.concatenate(pool_layer_lst, 3, name ="pool_layer") max_num = len(window_sizes) * filter_num pool_layer_flat = tf.keras.layers.Reshape([1, max_num], name = "pool_layer_flat")(pool_layer) dropout_layer = tf.keras.layers.Dropout(dropout_keep, name = "dropout_layer")(pool_layer_flat) return pool_layer_flat, dropout_layer # 将Movie的各个层一起做全连接 def get_movie_feature_layer(movie_id_embed_layer, movie_categories_embed_layer, dropout_layer): #第一层全连接 movie_id_fc_layer = tf.keras.layers.Dense(embed_dim, name="movie_id_fc_layer", activation='relu')(movie_id_embed_layer) movie_categories_fc_layer = tf.keras.layers.Dense(embed_dim, name="movie_categories_fc_layer", activation='relu')(movie_categories_embed_layer) #第二层全连接 movie_combine_layer = tf.keras.layers.concatenate([movie_id_fc_layer, movie_categories_fc_layer, dropout_layer], 2) movie_combine_layer = tf.keras.layers.Dense(200, activation='tanh')(movie_combine_layer) movie_combine_layer_flat = tf.keras.layers.Reshape([200], name="movie_combine_layer_flat")(movie_combine_layer) return movie_combine_layer, movie_combine_layer_flat # 构建计算图 MODEL_DIR = "./models" class mv_network(object): def __init__(self, batch_size=256): self.batch_size = batch_size self.best_loss = 9999 self.losses = {'train': [], 'test': []} # 获取输入占位符 uid, user_gender, user_age, user_job, movie_id, movie_categories, movie_titles = get_inputs() # 获取User的4个嵌入向量 uid_embed_layer, gender_embed_layer, age_embed_layer, job_embed_layer = get_user_embedding(uid, user_gender, user_age, user_job) # 得到用户特征 user_combine_layer, user_combine_layer_flat = get_user_feature_layer(uid_embed_layer, gender_embed_layer, age_embed_layer, job_embed_layer) # 获取电影ID的嵌入向量 movie_id_embed_layer = get_movie_id_embed_layer(movie_id) # 获取电影类型的嵌入向量 movie_categories_embed_layer = get_movie_categories_layers(movie_categories) # 获取电影名的特征向量 pool_layer_flat, dropout_layer = get_movie_cnn_layer(movie_titles) # 得到电影特征 movie_combine_layer, movie_combine_layer_flat = get_movie_feature_layer(movie_id_embed_layer, movie_categories_embed_layer, dropout_layer) # 计算出评分 # 将用户特征和电影特征做矩阵乘法得到一个预测评分的方案 inference = tf.keras.layers.Lambda(lambda layer: tf.reduce_sum(layer[0] * layer[1], axis=1), name="inference")( (user_combine_layer_flat, movie_combine_layer_flat)) inference = tf.keras.layers.Lambda(lambda layer: tf.expand_dims(layer, axis=1))(inference) # 将用户特征和电影特征作为输入,经过全连接,输出一个值的方案 # inference_layer = tf.keras.layers.concatenate([user_combine_layer_flat, movie_combine_layer_flat], # 1) # (?, 400) # 你可以使用下面这个全连接层,试试效果 # inference_dense = tf.keras.layers.Dense(64, kernel_regularizer=tf.nn.l2_loss, activation='relu')( # inference_layer) # inference = tf.keras.layers.Dense(1, name="inference")(inference_layer) # inference_dense self.model = tf.keras.Model( inputs=[uid, user_gender, user_age, user_job, movie_id, movie_categories, movie_titles], outputs=[inference]) self.model.summary() self.optimizer = tf.keras.optimizers.Adam(learning_rate) # MSE损失,将计算值回归到评分 self.ComputeLoss = tf.keras.losses.MeanSquaredError() self.ComputeMetrics = tf.keras.metrics.MeanAbsoluteError() if tf.io.gfile.exists(MODEL_DIR): # print('Removing existing model dir: {}'.format(MODEL_DIR)) # tf.io.gfile.rmtree(MODEL_DIR) pass else: tf.io.gfile.makedirs(MODEL_DIR) train_dir = os.path.join(MODEL_DIR, 'summaries', 'train') test_dir = os.path.join(MODEL_DIR, 'summaries', 'eval') # self.train_summary_writer = summary_ops_v2.create_file_writer(train_dir, flush_millis=10000) # self.test_summary_writer = summary_ops_v2.create_file_writer(test_dir, flush_millis=10000, name='test') checkpoint_dir = os.path.join(MODEL_DIR, 'checkpoints') self.checkpoint_prefix = os.path.join(checkpoint_dir, 'ckpt') self.checkpoint = tf.train.Checkpoint(model=self.model, optimizer=self.optimizer) # Restore variables on creation if a checkpoint exists. self.checkpoint.restore(tf.train.latest_checkpoint(checkpoint_dir)) def compute_loss(self, labels, logits): return tf.reduce_mean(tf.keras.losses.mse(labels, logits)) def compute_metrics(self, labels, logits): return tf.keras.metrics.mae(labels, logits) # @tf.function def train_step(self, x, y): # Record the operations used to compute the loss, so that the gradient # of the loss with respect to the variables can be computed. # metrics = 0 with tf.GradientTape() as tape: logits = self.model([x[0], x[1], x[2], x[3], x[4], x[5], x[6]], training=True) loss = self.ComputeLoss(y, logits) # loss = self.compute_loss(labels, logits) self.ComputeMetrics(y, logits) # metrics = self.compute_metrics(labels, logits) grads = tape.gradient(loss, self.model.trainable_variables) self.optimizer.apply_gradients(zip(grads, self.model.trainable_variables)) return loss, logits def training(self, features, targets_values, epochs=5, log_freq=50): for epoch_i in range(epochs): # 将数据集分成训练集和测试集,随机种子不固定 train_X, test_X, train_y, test_y = train_test_split(features, targets_values, test_size=0.2, random_state=0) train_batches = get_batches(train_X, train_y, self.batch_size) batch_num = (len(train_X) // self.batch_size) train_start = time.time() # with self.train_summary_writer.as_default(): if True: start = time.time() # Metrics are stateful. They accumulate values and return a cumulative # result when you call .result(). Clear accumulated values with .reset_states() avg_loss = tf.keras.metrics.Mean('loss', dtype=tf.float32) # avg_mae = tf.keras.metrics.Mean('mae', dtype=tf.float32) # Datasets can be iterated over like any other Python iterable. for batch_i in range(batch_num): x, y = next(train_batches) categories = np.zeros([self.batch_size, 18]) for i in range(self.batch_size): categories[i] = x.take(6, 1)[i] titles = np.zeros([self.batch_size, sentences_size]) for i in range(self.batch_size): titles[i] = x.take(5, 1)[i] loss, logits = self.train_step([np.reshape(x.take(0, 1), [self.batch_size, 1]).astype(np.float32), np.reshape(x.take(2, 1), [self.batch_size, 1]).astype(np.float32), np.reshape(x.take(3, 1), [self.batch_size, 1]).astype(np.float32), np.reshape(x.take(4, 1), [self.batch_size, 1]).astype(np.float32), np.reshape(x.take(1, 1), [self.batch_size, 1]).astype(np.float32), categories.astype(np.float32), titles.astype(np.float32)], np.reshape(y, [self.batch_size, 1]).astype(np.float32)) avg_loss(loss) # avg_mae(metrics) self.losses['train'].append(loss) if tf.equal(self.optimizer.iterations % log_freq, 0): # summary_ops_v2.scalar('loss', avg_loss.result(), step=self.optimizer.iterations) # summary_ops_v2.scalar('mae', self.ComputeMetrics.result(), step=self.optimizer.iterations) # summary_ops_v2.scalar('mae', avg_mae.result(), step=self.optimizer.iterations) rate = log_freq / (time.time() - start) print('Step #{}\tEpoch {:>3} Batch {:>4}/{} Loss: {:0.6f} mae: {:0.6f} ({} steps/sec)'.format( self.optimizer.iterations.numpy(), epoch_i, batch_i, batch_num, loss, (self.ComputeMetrics.result()), rate)) # print('Step #{}\tLoss: {:0.6f} mae: {:0.6f} ({} steps/sec)'.format( # self.optimizer.iterations.numpy(), loss, (avg_mae.result()), rate)) avg_loss.reset_states() self.ComputeMetrics.reset_states() # avg_mae.reset_states() start = time.time() train_end = time.time() print( '\nTrain time for epoch #{} ({} total steps): {}'.format(epoch_i + 1, self.optimizer.iterations.numpy(), train_end - train_start)) # with self.test_summary_writer.as_default(): self.testing((test_X, test_y), self.optimizer.iterations) # self.checkpoint.save(self.checkpoint_prefix) self.export_path = os.path.join(MODEL_DIR, 'export') tf.saved_model.save(self.model, self.export_path) def testing(self, test_dataset, step_num): test_X, test_y = test_dataset test_batches = get_batches(test_X, test_y, self.batch_size) """Perform an evaluation of `model` on the examples from `dataset`.""" avg_loss = tf.keras.metrics.Mean('loss', dtype=tf.float32) # avg_mae = tf.keras.metrics.Mean('mae', dtype=tf.float32) batch_num = (len(test_X) // self.batch_size) for batch_i in range(batch_num): x, y = next(test_batches) categories = np.zeros([self.batch_size, 18]) for i in range(self.batch_size): categories[i] = x.take(6, 1)[i] titles = np.zeros([self.batch_size, sentences_size]) for i in range(self.batch_size): titles[i] = x.take(5, 1)[i] logits = self.model([np.reshape(x.take(0, 1), [self.batch_size, 1]).astype(np.float32), np.reshape(x.take(2, 1), [self.batch_size, 1]).astype(np.float32), np.reshape(x.take(3, 1), [self.batch_size, 1]).astype(np.float32), np.reshape(x.take(4, 1), [self.batch_size, 1]).astype(np.float32), np.reshape(x.take(1, 1), [self.batch_size, 1]).astype(np.float32), categories.astype(np.float32), titles.astype(np.float32)], training=False) test_loss = self.ComputeLoss(np.reshape(y, [self.batch_size, 1]).astype(np.float32), logits) avg_loss(test_loss) # 保存测试损失 self.losses['test'].append(test_loss) self.ComputeMetrics(np.reshape(y, [self.batch_size, 1]).astype(np.float32), logits) # avg_loss(self.compute_loss(labels, logits)) # avg_mae(self.compute_metrics(labels, logits)) print('Model test set loss: {:0.6f} mae: {:0.6f}'.format(avg_loss.result(), self.ComputeMetrics.result())) # print('Model test set loss: {:0.6f} mae: {:0.6f}'.format(avg_loss.result(), avg_mae.result())) # summary_ops_v2.scalar('loss', avg_loss.result(), step=step_num) # summary_ops_v2.scalar('mae', self.ComputeMetrics.result(), step=step_num) # summary_ops_v2.scalar('mae', avg_mae.result(), step=step_num) if avg_loss.result() < self.best_loss: self.best_loss = avg_loss.result() print("best loss = {}".format(self.best_loss)) self.checkpoint.save(self.checkpoint_prefix) def forward(self, xs): predictions = self.model(xs) # logits = tf.nn.softmax(predictions) return predictions # 取得batch def get_batches(Xs, ys, batch_size): for start in range(0, len(Xs), batch_size): end = min(start + batch_size, len(Xs)) yield Xs[start:end], ys[start:end] # 训练网络 # 将用户特征和电影特征做矩阵乘法得到一个预测评分的训练 mv_net=mv_network() mv_net.training(features, targets_values, epochs=5) # 显示训练Loss # %matplotlib inline # %config InlineBackend.figure_format = 'retina' plt.plot(mv_net.losses['train'], label='Training loss') plt.legend() _ = plt.ylim() plt.savefig('./Training_loss.png', dpi=300) plt.show() # 显示测试Loss # 迭代次数再增加一些,下降的趋势会明显一些 plt.plot(mv_net.losses['test'], label='Test loss') plt.legend() _ = plt.ylim() plt.savefig('./Test_loss.png', dpi=300) plt.show() # 指定用户和电影进行评分 # 这部分就是对网络做正向传播,计算得到预测的评分 def rating_movie(mv_net, user_id_val, movie_id_val): categories = np.zeros([1, 18]) categories[0] = movies.values[movieid2idx[movie_id_val]][2] titles = np.zeros([1, sentences_size]) titles[0] = movies.values[movieid2idx[movie_id_val]][1] inference_val = mv_net.model([np.reshape(users.values[user_id_val - 1][0], [1, 1]), np.reshape(users.values[user_id_val - 1][1], [1, 1]), np.reshape(users.values[user_id_val - 1][2], [1, 1]), np.reshape(users.values[user_id_val - 1][3], [1, 1]), np.reshape(movies.values[movieid2idx[movie_id_val]][0], [1, 1]), categories, titles]) return (inference_val.numpy()) print(rating_movie(mv_net, 234, 1401)) # 生成Movie特征矩阵 # 将训练好的电影特征组合成电影特征矩阵并保存到本地 movie_layer_model = keras.models.Model(inputs=[mv_net.model.input[4], mv_net.model.input[5], mv_net.model.input[6]], outputs=mv_net.model.get_layer("movie_combine_layer_flat").output) movie_matrics = [] for item in movies.values: categories = np.zeros([1, 18]) categories[0] = item.take(2) titles = np.zeros([1, sentences_size]) titles[0] = item.take(1) movie_combine_layer_flat_val = movie_layer_model([np.reshape(item.take(0), [1, 1]), categories, titles]) movie_matrics.append(movie_combine_layer_flat_val) pickle.dump((np.array(movie_matrics).reshape(-1, 200)), open('movie_matrics.p', 'wb')) movie_matrics = pickle.load(open('movie_matrics.p', mode='rb')) # 生成User特征矩阵 # 将训练好的用户特征组合成用户特征矩阵并保存到本地 user_layer_model = keras.models.Model(inputs=[mv_net.model.input[0], mv_net.model.input[1], mv_net.model.input[2], mv_net.model.input[3]], outputs=mv_net.model.get_layer("user_combine_layer_flat").output) users_matrics = [] for item in users.values: user_combine_layer_flat_val = user_layer_model([np.reshape(item.take(0), [1, 1]), np.reshape(item.take(1), [1, 1]), np.reshape(item.take(2), [1, 1]), np.reshape(item.take(3), [1, 1])]) users_matrics.append(user_combine_layer_flat_val) pickle.dump((np.array(users_matrics).reshape(-1, 200)), open('users_matrics.p', 'wb')) users_matrics = pickle.load(open('users_matrics.p', mode='rb')) # 开始推荐电影 # 使用生产的用户特征矩阵和电影特征矩阵做电影推荐 # # 推荐同类型的电影 # 思路是计算当前看的电影特征向量与整个电影特征矩阵的余弦相似度,取相似度最大的top_k个,这里加了些随机选择在里面,保证每次的推荐稍稍有些不同。 def recommend_same_type_movie(movie_id_val, top_k=20): norm_movie_matrics = tf.sqrt(tf.reduce_sum(tf.square(movie_matrics), 1, keepdims=True)) normalized_movie_matrics = movie_matrics / norm_movie_matrics # 推荐同类型的电影 probs_embeddings = (movie_matrics[movieid2idx[movie_id_val]]).reshape([1, 200]) probs_similarity = tf.matmul(probs_embeddings, tf.transpose(normalized_movie_matrics)) sim = (probs_similarity.numpy()) # results = (-sim[0]).argsort()[0:top_k] # print(results) print("您看的电影是:{}".format(movies_orig[movieid2idx[movie_id_val]])) print("以下是给您的推荐:") p = np.squeeze(sim) p[np.argsort(p)[:-top_k]] = 0 p = p / np.sum(p) results = set() while len(results) != 5: c = np.random.choice(3883, 1, p=p)[0] results.add(c) for val in (results): print(val) print(movies_orig[val]) return results print(recommend_same_type_movie(1401, 20)) # 推荐您喜欢的电影 # 思路是使用用户特征向量与电影特征矩阵计算所有电影的评分,取评分最高的top_k个,同样加了些随机选择部分。 def recommend_your_favorite_movie(user_id_val, top_k=10): # 推荐您喜欢的电影 probs_embeddings = (users_matrics[user_id_val - 1]).reshape([1, 200]) probs_similarity = tf.matmul(probs_embeddings, tf.transpose(movie_matrics)) sim = (probs_similarity.numpy()) # print(sim.shape) # results = (-sim[0]).argsort()[0:top_k] # print(results) # sim_norm = probs_norm_similarity.eval() # print((-sim_norm[0]).argsort()[0:top_k]) print("以下是给您的推荐:") p = np.squeeze(sim) p[np.argsort(p)[:-top_k]] = 0 p = p / np.sum(p) results = set() while len(results) != 5: c = np.random.choice(3883, 1, p=p)[0] results.add(c) for val in (results): print(val) print(movies_orig[val]) return results print(recommend_your_favorite_movie(234, 10)) # 看过这个电影的人还看了(喜欢)哪些电影 # 首先选出喜欢某个电影的top_k个人,得到这几个人的用户特征向量。 # 然后计算这几个人对所有电影的评分 # 选择每个人评分最高的电影作为推荐 # 同样加入了随机选择 def recommend_other_favorite_movie(movie_id_val, top_k=20): probs_movie_embeddings = (movie_matrics[movieid2idx[movie_id_val]]).reshape([1, 200]) probs_user_favorite_similarity = tf.matmul(probs_movie_embeddings, tf.transpose(users_matrics)) favorite_user_id = np.argsort(probs_user_favorite_similarity.numpy())[0][-top_k:] # print(normalized_users_matrics.numpy().shape) # print(probs_user_favorite_similarity.numpy()[0][favorite_user_id]) # print(favorite_user_id.shape) print("您看的电影是:{}".format(movies_orig[movieid2idx[movie_id_val]])) print("喜欢看这个电影的人是:{}".format(users_orig[favorite_user_id - 1])) probs_users_embeddings = (users_matrics[favorite_user_id - 1]).reshape([-1, 200]) probs_similarity = tf.matmul(probs_users_embeddings, tf.transpose(movie_matrics)) sim = (probs_similarity.numpy()) # results = (-sim[0]).argsort()[0:top_k] # print(results) # print(sim.shape) # print(np.argmax(sim, 1)) p = np.argmax(sim, 1) print("喜欢看这个电影的人还喜欢看:") if len(set(p)) < 5: results = set(p) else: results = set() while len(results) != 5: c = p[random.randrange(top_k)] results.add(c) for val in (results): print(val) print(movies_orig[val]) return results print(recommend_other_favorite_movie(1401, 20))
更加详细的介绍和数据参考原文:
https://soyoger.blog.csdn.net/article/details/108729404
https://github.com/chengstone/movie_recommender
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