codekingpro/portable-devtools

1from typing import Any2 3from langchain_core._api import deprecated4from langchain_core.messages import BaseMessage, get_buffer_string5from typing_extensions import override6 7from langchain_classic.memory.chat_memory import BaseChatMemory8 9 10@deprecated(11    since="0.3.1",12    removal="2.0.0",13    alternative="langchain.agents.create_agent",14    addendum=(15        "For agents that need to remember prior interactions, use "16        "`create_agent` with checkpointing or the `Store` API. See "17        "https://docs.langchain.com/oss/python/langchain/short-term-memory and "18        "https://docs.langchain.com/oss/python/langchain/long-term-memory"19    ),20)21class ConversationBufferWindowMemory(BaseChatMemory):22    """Use to keep track of the last k turns of a conversation.23 24    If the number of messages in the conversation is more than the maximum number25    of messages to keep, the oldest messages are dropped.26    """27 28    human_prefix: str = "Human"29    ai_prefix: str = "AI"30    memory_key: str = "history"31    k: int = 532    """Number of messages to store in buffer."""33 34    @property35    def buffer(self) -> str | list[BaseMessage]:36        """String buffer of memory."""37        return self.buffer_as_messages if self.return_messages else self.buffer_as_str38 39    @property40    def buffer_as_str(self) -> str:41        """Exposes the buffer as a string in case return_messages is False."""42        messages = self.chat_memory.messages[-self.k * 2 :] if self.k > 0 else []43        return get_buffer_string(44            messages,45            human_prefix=self.human_prefix,46            ai_prefix=self.ai_prefix,47        )48 49    @property50    def buffer_as_messages(self) -> list[BaseMessage]:51        """Exposes the buffer as a list of messages in case return_messages is True."""52        return self.chat_memory.messages[-self.k * 2 :] if self.k > 0 else []53 54    @property55    def memory_variables(self) -> list[str]:56        """Will always return list of memory variables."""57        return [self.memory_key]58 59    @override60    def load_memory_variables(self, inputs: dict[str, Any]) -> dict[str, Any]:61        """Return history buffer."""62        return {self.memory_key: self.buffer}63