CassandraByteStore#

class langchain_community.storage.cassandra.CassandraByteStore(table: str, *, session: Session | None = None, keyspace: str | None = None, setup_mode: SetupMode = SetupMode.SYNC)[source]#

A ByteStore implementation using Cassandra as the backend.

Parameters:

table (str) – The name of the table to use.
session (Optional[Session]) – A Cassandra session object. If not provided, it will be resolved from the cassio config.
keyspace (Optional[str]) – The keyspace to use. If not provided, it will be resolved from the cassio config.
setup_mode (SetupMode) – The setup mode to use. Default is SYNC (SetupMode.SYNC).

Methods

`__init__`(table, *[, session, keyspace, ...])
`aensure_db_setup`()	Ensure that the DB setup is finished.
`amdelete`(keys)	Async delete the given keys and their associated values.
`amget`(keys)	Async get the values associated with the given keys.
`amset`(key_value_pairs)	Async set the values for the given keys.
`ayield_keys`(*[, prefix])	Async get an iterator over keys that match the given prefix.
`ensure_db_setup`()	Ensure that the DB setup is finished.
`get_delete_statement`()	Get the prepared delete statement for the table.
`get_insert_statement`()	Get the prepared insert statement for the table.
`get_select_statement`()	Get the prepared select statement for the table.
`mdelete`(keys)	Delete the given keys and their associated values.
`mget`(keys)	Get the values associated with the given keys.
`mset`(key_value_pairs)	Set the values for the given keys.
`yield_keys`(*[, prefix])	Get an iterator over keys that match the given prefix.

__init__(table: str, *, session: Session | None = None, keyspace: str | None = None, setup_mode: SetupMode = SetupMode.SYNC) → None[source]#

Parameters:

table (str) –
session (Optional[Session]) –
keyspace (Optional[str]) –
setup_mode (SetupMode) –

Return type:

None

async aensure_db_setup() → None[source]#

Ensure that the DB setup is finished. If not, wait for it.

Return type:: None

async amdelete(keys: Sequence[str]) → None[source]#

Async delete the given keys and their associated values.

Parameters:: keys (Sequence[K]) – A sequence of keys to delete.
Return type:: None

async amget(keys: Sequence[str]) → List[bytes | None][source]#

Async get the values associated with the given keys.

Parameters:: keys (Sequence[K]) – A sequence of keys.
Returns:: A sequence of optional values associated with the keys. If a key is not found, the corresponding value will be None.
Return type:: List[bytes | None]

async amset(key_value_pairs: Sequence[Tuple[str, bytes]]) → None[source]#

Async set the values for the given keys.

Parameters:: key_value_pairs (Sequence[Tuple[K, V]]) – A sequence of key-value pairs.
Return type:: None

async ayield_keys(*, prefix: str | None = None) → AsyncIterator[str][source]#

Async get an iterator over keys that match the given prefix.

Parameters:: prefix (str) – The prefix to match.
Yields:: Iterator[K | str] – An iterator over keys that match the given prefix. This method is allowed to return an iterator over either K or str depending on what makes more sense for the given store.
Return type:: AsyncIterator[str]

ensure_db_setup() → None[source]#

Ensure that the DB setup is finished. If not, raise a ValueError.

Return type:: None

get_delete_statement() → PreparedStatement[source]#

Get the prepared delete statement for the table. If not available, prepare it.

Returns:: The prepared statement.
Return type:: PreparedStatement

get_insert_statement() → PreparedStatement[source]#

Get the prepared insert statement for the table. If not available, prepare it.

Returns:: The prepared statement.
Return type:: PreparedStatement

get_select_statement() → PreparedStatement[source]#

Get the prepared select statement for the table. If not available, prepare it.

Returns:: The prepared statement.
Return type:: PreparedStatement

mdelete(keys: Sequence[str]) → None[source]#

Delete the given keys and their associated values.

Parameters:: keys (Sequence[K]) – A sequence of keys to delete.
Return type:: None

mget(keys: Sequence[str]) → List[bytes | None][source]#

Get the values associated with the given keys.

Parameters:: keys (Sequence[K]) – A sequence of keys.
Returns:: A sequence of optional values associated with the keys. If a key is not found, the corresponding value will be None.
Return type:: List[bytes | None]

mset(key_value_pairs: Sequence[Tuple[str, bytes]]) → None[source]#

Set the values for the given keys.

Parameters:: key_value_pairs (Sequence[Tuple[K, V]]) – A sequence of key-value pairs.
Return type:: None

yield_keys(*, prefix: str | None = None) → Iterator[str][source]#

Get an iterator over keys that match the given prefix.

Parameters:: prefix (str) – The prefix to match.
Yields:: Iterator[K | str] – An iterator over keys that match the given prefix. This method is allowed to return an iterator over either K or str depending on what makes more sense for the given store.
Return type:: Iterator[str]

Examples using CassandraByteStore

CassandraByteStore