723LTtQd

1from cassandra.cluster import Cluster
2from cassandra.query import dict_factory
3
4class CassandraClient:
5    def __init__(self, ip='127.0.0.1', port=9042, kayspace='user_ratings', table='user_ratings'):
6        cluster = Cluster([ip], port=port)
7        self.session = cluster.connect()
8        self.keyspace = kayspace
9        self.table = table
10
11        self.columns = {
12            'userID': 'int',
13            'movieID': 'int',
14            'rating': 'float',
15            'genre_Action': 'float',
16            'genre_Adventure': 'float',
17            'genre_Animation': 'float',
18            'genre_Children': 'float',
19            'genre_Comedy': 'float',
20            'genre_Crime': 'float',
21            'genre_Documentary': 'float',
22            'genre_Drama': 'float',
23            'genre_Fantasy': 'float',
24            'genre_Film_Noir': 'float',
25            'genre_Horror': 'float',
26            'genre_IMAX': 'float',
27            'genre_Musical': 'float',
28            'genre_Mystery': 'float',
29            'genre_Romance': 'float',
30            'genre_Sci_Fi': 'float',
31            'genre_Short': 'float',
32            'genre_Thriller': 'float',
33            'genre_War': 'float',
34            'genre_Western': 'float'
35        }
36
37
38    def create_keyspace(self):
39        self.session.execute("""
40            CREATE KEYSPACE IF NOT EXISTS """+self.keyspace+"""
41            WITH replication = { 'class': 'SimpleStrategy', 'replication_factor': '1' }
42            """)
43
44    def create_table(self):
45        self.session.execute("CREATE TABLE IF NOT EXISTS {}.{}".format(self.keyspace,self.table)+
46            " (" + "".join("{} {},\n".format(it[0], it[1]) for it in self.columns.items()) +
47            "PRIMARY KEY(userID, movieID)) ")
48
49    def push_data_table(self, data):
50        _dict = {}
51        for el in self.columns.keys():
52            _dict[el] = data[el]
53
54        self.session.execute("INSERT INTO {}.{}".format(self.keyspace, self.table)+
55            " (" + "".join("{}, ".format(it) for it in self.columns.keys())[:-2]+
56            ") VALUES (" + "".join("%({})s, ".format(it) for it in self.columns.keys())[:-2] +
57            ")",
58            _dict
59        )
60
61    def get_data_table(self):
62        result = []
63        rows = self.session.execute("SELECT " + "".join('{}, '.format(it) for it in self.columns.keys())[:-2] +
64        " FROM {}.{};".format(self.keyspace, self.table))
65       
66        for row in rows:
67            _dict = {}
68            for i, el in enumerate(self.columns):
69                _dict[el] = row[i]
70            result.append(_dict)
71        return result