Memory, base class¶

This implements the Cassandra-specific I/O facilities, and is then used by LangChain to power every other, more sophisticated, abstraction around keeping chat memory.

In [1]:

from langchain.memory import CassandraChatMessageHistory

from langchain.memory import CassandraChatMessageHistory

In [2]:

from cqlsession import getCQLSession, getCQLKeyspace
astraSession = getCQLSession()
astraKeyspace = getCQLKeyspace()

from cqlsession import getCQLSession, getCQLKeyspace astraSession = getCQLSession() astraKeyspace = getCQLKeyspace()

/home/stefano/.virtualenvs/langchain-cassio-3.10/lib/python3.10/site-packages/cassandra/io/asyncorereactor.py:34: DeprecationWarning: The asyncore module is deprecated and will be removed in Python 3.12. The recommended replacement is asyncio
  import asyncore
/home/stefano/.virtualenvs/langchain-cassio-3.10/lib/python3.10/site-packages/cassandra/datastax/cloud/__init__.py:173: DeprecationWarning: ssl.PROTOCOL_TLS is deprecated
  ssl_context = SSLContext(PROTOCOL_TLS)
/home/stefano/.virtualenvs/langchain-cassio-3.10/lib/python3.10/site-packages/cassandra/io/asyncorereactor.py:347: DeprecationWarning: ssl.match_hostname() is deprecated
  self._connect_socket()

In [3]:

message_history = CassandraChatMessageHistory(
    session_id='test-session',
    session=astraSession,
    keyspace='langchain',
    ttl_seconds = 3600,
)
message_history.clear()

message_history = CassandraChatMessageHistory( session_id='test-session', session=astraSession, keyspace='langchain', ttl_seconds = 3600, ) message_history.clear()

In [4]:

message_history.messages

message_history.messages

Out[4]:

[]

In [5]:

message_history.add_user_message('Hello, I am human.')

message_history.add_user_message('Hello, I am human.')

In [6]:

message_history.add_ai_message('Hello, I am the bot.')

message_history.add_ai_message('Hello, I am the bot.')

In [7]:

message_history.messages

message_history.messages

Out[7]:

[HumanMessage(content='Hello, I am human.', additional_kwargs={}, example=False),
 AIMessage(content='Hello, I am the bot.', additional_kwargs={}, example=False)]

In [8]:

message_history.clear()

message_history.clear()

In [9]:

message_history.messages

message_history.messages

Out[9]:

[]