yg6gc1wU

1from cassandra.cluster import Cluster
2from cassandra.query import dict_factory
3import Lab4
4
5KEYSPACE = "rating_keyspace"
6USER_TABLE = "user_rated_movies"
7AVG_GENRE_RATINGS_FOR_USER = "avg_genre_ratings_for_user"
8
9class CassClient:
10    def __init__(self):
11        cluster = Cluster(['127.0.0.1'], port=9042)
12        self.session = cluster.connect()
13        self.create_keyspace()
14        self.session.set_keyspace(KEYSPACE)
15        self.session.row_factory = dict_factory
16
17    def create_keyspace(self):
18        self.session.execute("""        
19            CREATE KEYSPACE IF NOT EXISTS """+KEYSPACE+"""
20            WITH replication = { 'class': 'SimpleStrategy', 'replication_factor': '1' }
21            """)
22
23    def create_table_query(self, keyspace, table, primaryKey, additionalColumns):
24        output = """
25        CREATE TABLE IF NOT EXISTS """ + keyspace + """.""" + table + """ ("""
26        for column_name, type in additionalColumns.items():
27            output = output + str(column_name) + ' ' + str(type) + ', '
28        output = output + 'PRIMARY_KEY(' + primaryKey + ')'
29        output = output + \
30            """ )"""
31        return output
32
33    def query_helper(self, tableName):
34        _, genres_column_names = Lab4.merge(1)
35        genres_num = len(genres_column_names)
36        genres_column_names = [genre.replace('-', '_') for genre in genres_column_names]
37        if USER_TABLE == tableName:
38            genres_column_names.insert(0, "rating")
39            genres_column_names.insert(0, "movie_id")
40            genres_column_names.insert(0, "user_id")
41            types = ['int', 'int', 'float']
42            for _ in range(genres_num):
43                types.append('int')
44        else:
45            genres_column_names.insert(0, "user_id")
46            types = ['int']
47            for _ in range (genres_num):
48                types.append('float')
49        return dict(zip(genres_column_names, types))
50
51    def create_avg_genre_ratings_for_user_table(self):
52        query = self.create_table_query(KEYSPACE, AVG_GENRE_RATINGS_FOR_USER, 'user_id', self.query_helper(AVG_GENRE_RATINGS_FOR_USER))
53        self.session.execute(query)
54
55    def create_user_rated_movies(self):
56
57
58    # def push_data_table(session ,keyspace, table, userId, values):
59    #     session.execute("""
60    #     INSERT INTO """+keyspace+"""."""+table+"""(
61    #     user_id, avg_movie_rating)
62    #     VALUES(%(user_id)s, %(values)s)
63    #     """,
64    #                     {
65    #                        'user_id': userId,
66    #                         'profile': values
67    #                     })
68
69    def get_data_table(self, keyspace, table):
70        rows = self.session.execute("SELECT * FROM "+keyspace+"."+table+";")
71        for row in rows:
72            print(row)
73
74    def clear_table(self, keyspace, table):
75        self.session.execute("TRUNCATE "+keyspace+"."+table+";")
76
77    def delete_table(self, keyspace, table):
78        self.session.execute("DROP TABLE "+keyspace+"."+table+";")
79
80    if __name__ == "__main__":
81        # keyspace = "user_ratings"
82        # table = "user_avg_rating"
83        # cluster = Cluster(['127.0.0.1'], port=9042)
84        # session = cluster.connect()
85        # create_keyspace(session, keyspace)
86        # session.set_keyspace(keyspace)
87        # session.row_factory = dict_factory
88        # create_table(session, keyspace, table)
89        #
90        # push_data_table(session, keyspace, table, userId=1337, avgMovieRating=4.2)
91        # get_data_table(session, keyspace, table)
92        # clear_table(session, keyspace, table)
93        # get_data_table(session, keyspace, table)
94        # delete_table(session, keyspace, table)