def process_item_sequence(rating_data):
sequences = rating_data.filter(F.col("rating") >= 3.5).groupBy("userId")\
.agg(udf_combine_movies_by_timeline(F.collect_list("movieId"), F.collect_list("timestamp")).alias("movieIds"))\
.withColumn("movieIdStr", F.array_join(F.col("movieIds"), " "))
print_info(sequences, message="after build movieIdStr: ")
sequences = sequences.select("movieIds")
return sequences
def extract_and_save_movie_features_to_redis(features: DataFrame):
print_info(features)
samples = features.withColumn("movieRowNum",
F.row_number().over(
sql.Window.partitionBy("movieId").orderBy(F.col("timestamp").desc()))) \
.filter(F.col("movieRowNum") == 1) \
.select("movieId", "releaseYear", "movieGenre1", "movieGenre2", "movieGenre3",
"movieRatingCount", "movieAvgRating", "movieRatingStddev").na.fill("")
pool = redis.ConnectionPool(host='localhost',
port=6379,
decode_responses=True)
r = redis.Redis(connection_pool=pool)
sample_array = samples.collect()
print("total user size: %d" % len(sample_array))
insert_movie_number = 0
movie_count = len(sample_array)
for sample in sample_array:
movie_key = Config.movie_feature_prefix + sample["movieId"]
value_map = dict()
value_map["releaseYear"] = sample["releaseYear"]
value_map["movieGenre1"] = sample["movieGenre1"]
value_map["movieGenre2"] = sample["movieGenre2"]
value_map["movieGenre3"] = sample["movieGenre3"]
value_map["movieRatingCount"] = sample["movieRatingCount"]
value_map["movieAvgRating"] = sample["movieAvgRating"]
value_map["movieRatingStddev"] = sample["movieRatingStddev"]
r.hmset(movie_key, value_map)
insert_movie_number += 1
if insert_movie_number % 100 == 0:
print("%d/%d..." % (insert_movie_number, movie_count))
r.close()
return samples
def add_sample_label(data):
print_info(data)
sample_count = data.count()
data.groupBy("rating").count().orderBy("rating")\
.withColumn("percentage", F.col("count")/sample_count)\
.show()
data = data.withColumn("label",
F.when(F.col("rating") >= 3.5, 1).otherwise(0))
print_info(data)
return data
def generate_transition_matrix(movie_sequences: DataFrame):
print_info(movie_sequences)
pair_data = movie_sequences.rdd.flatMap(build_pair_data)
print(pair_data.take(20))
pair_data_with_weight = pair_data.groupBy(lambda x: x[0]).map(
build_movieId_weight).collectAsMap()
item2weight = {}
total_length = movie_sequences.count()
for movieId, id2weight in pair_data_with_weight.items():
item2weight[movieId] = len(id2weight) * 1.0 / total_length
return pair_data_with_weight, item2weight
def add_user_features(data):
# find positive rating list of each userId
features = data.withColumn("userPositiveHistory",
F.collect_list(F.when(F.col("label") == 1, F.col("movieId")).otherwise(F.lit(None)))
.over(
sql.Window.partitionBy("userId").orderBy(F.col("timestamp")).rowsBetween(-100, -1)
))\
.withColumn("userPositiveHistory", F.reverse(F.col("userPositiveHistory"))) \
.withColumn("userRatedMovie1", F.col("userPositiveHistory").getItem(0)) \
.withColumn("userRatedMovie2", F.col("userPositiveHistory").getItem(1)) \
.withColumn("userRatedMovie3", F.col("userPositiveHistory").getItem(2)) \
.withColumn("userRatedMovie4", F.col("userPositiveHistory").getItem(3)) \
.withColumn("userRatedMovie5", F.col("userPositiveHistory").getItem(4)) \
.withColumn("userRatingCount",
F.count(F.lit(1)).over(sql.Window.partitionBy("userId")
.orderBy(F.col("timestamp")).rowsBetween(-100, -1))) \
.withColumn("userAvgReleaseYear",
F.avg(F.col("releaseYear")).over(sql.Window.partitionBy("userId")
.orderBy(F.col("timestamp")).rowsBetween(-100, -1)).cast("integer")) \
.withColumn("userReleaseYearStddev",
F.stddev(F.col("releaseYear")).over(sql.Window.partitionBy("userId")
.orderBy(F.col("timestamp")).rowsBetween(-100, -1)).cast("integer")) \
.withColumn("userAvgRating",
F.format_number(F.avg(F.col("rating")).over(sql.Window.partitionBy("userId")
.orderBy("timestamp").rowsBetween(-100, -1)), Config.NUMBER_PRECISION)) \
.withColumn("userRatingStddev",
F.format_number(F.stddev(F.col("rating")).over(sql.Window.partitionBy("userId")
.orderBy("timestamp").rowsBetween(-100, -1)), Config.NUMBER_PRECISION)) \
.withColumn("userGenres",
udf_extract_genres(F.collect_list(F.when(F.col("label") == 1, F.col("genres")).otherwise(F.lit(None)))
.over(sql.Window.partitionBy("userId").orderBy("timestamp").rowsBetween(-100, -1)))) \
.na.fill(0) \
.withColumn("userReleaseYearStddev", F.format_number(F.col("userReleaseYearStddev"), Config.NUMBER_PRECISION)) \
.withColumn("userGenre1", F.col("userGenres").getItem(0)) \
.withColumn("userGenre2", F.col("userGenres").getItem(1)) \
.withColumn("userGenre3", F.col("userGenres").getItem(2)) \
.withColumn("userGenre4", F.col("userGenres").getItem(3)) \
.withColumn("userGenre5", F.col("userGenres").getItem(4)) \
.drop("genres", "userGenres", "userPositiveHistory") \
.filter(F.col("userRatingCount") > 1)
print_info(features, topN=20)
return features
def add_movie_features(data, rating_with_label):
# combine movie data and label
data = rating_with_label.join(data, on=['movieId'], how="left")
# get release year
data = data.withColumn("releaseYear", udf_get_year_from_title(F.col("title")))\
.withColumn("title", udf_get_title_from_title(F.col("title")))\
.drop("title")
# split genres to 3 columns
data = data.withColumn("genre1", F.split(F.col("genres"), "\\|").getItem(0)) \
.withColumn("genre2", F.split(F.col("genres"), "\\|").getItem(1)) \
.withColumn("genre3", F.split(F.col("genres"), "\\|").getItem(2))
# get rating's avg, std
rating_features = data.groupBy("movieId").agg(
F.count(F.lit(1)).alias("movieRatingCount"),
F.format_number(F.avg(F.col("rating")), Config.NUMBER_PRECISION).alias("AvgMovieRating"),
F.stddev(F.col("rating")).alias("StdMovieRating")).na.fill(0)\
.withColumn("StdMovieRating", F.format_number(F.col("StdMovieRating"), Config.NUMBER_PRECISION))
data = data.join(rating_features, on=["movieId"], how="left")
print_info(data)
return data
