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133 lines
4.8 KiB
Python
133 lines
4.8 KiB
Python
"""Memory modules for conversation prompts."""
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from typing import Any, Dict, List
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from pydantic import BaseModel, Field, root_validator
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from langchain.chains.base import Memory
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from langchain.chains.conversation.prompt import SUMMARY_PROMPT
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from langchain.chains.llm import LLMChain
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from langchain.llms.base import BaseLLM
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from langchain.prompts.base import BasePromptTemplate
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def _get_prompt_input_key(inputs: Dict[str, Any], memory_variables: List[str]) -> str:
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# "stop" is a special key that can be passed as input but is not used to
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# format the prompt.
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prompt_input_keys = list(set(inputs).difference(memory_variables + ["stop"]))
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if len(prompt_input_keys) != 1:
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raise ValueError(f"One input key expected got {prompt_input_keys}")
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return prompt_input_keys[0]
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class ConversationBufferMemory(Memory, BaseModel):
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"""Buffer for storing conversation memory."""
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buffer: str = ""
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memory_key: str = "history" #: :meta private:
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@property
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def memory_variables(self) -> List[str]:
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"""Will always return list of memory variables.
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:meta private:
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"""
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return [self.memory_key]
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def load_memory_variables(self, inputs: Dict[str, Any]) -> Dict[str, str]:
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"""Return history buffer."""
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return {self.memory_key: self.buffer}
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def save_context(self, inputs: Dict[str, Any], outputs: Dict[str, str]) -> None:
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"""Save context from this conversation to buffer."""
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prompt_input_key = _get_prompt_input_key(inputs, self.memory_variables)
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if len(outputs) != 1:
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raise ValueError(f"One output key expected, got {outputs.keys()}")
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human = "Human: " + inputs[prompt_input_key]
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ai = "AI: " + outputs[list(outputs.keys())[0]]
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self.buffer += "\n" + "\n".join([human, ai])
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def clear(self) -> None:
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"""Clear memory contents."""
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self.buffer = ""
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class ConversationalBufferWindowMemory(Memory, BaseModel):
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"""Buffer for storing conversation memory."""
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buffer: List[str] = Field(default_factory=list)
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memory_key: str = "history" #: :meta private:
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k: int = 5
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@property
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def memory_variables(self) -> List[str]:
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"""Will always return list of memory variables.
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:meta private:
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"""
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return [self.memory_key]
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def load_memory_variables(self, inputs: Dict[str, Any]) -> Dict[str, str]:
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"""Return history buffer."""
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return {self.memory_key: "\n".join(self.buffer[-self.k :])}
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def save_context(self, inputs: Dict[str, Any], outputs: Dict[str, str]) -> None:
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"""Save context from this conversation to buffer."""
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prompt_input_key = _get_prompt_input_key(inputs, self.memory_variables)
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if len(outputs) != 1:
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raise ValueError(f"One output key expected, got {outputs.keys()}")
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human = "Human: " + inputs[prompt_input_key]
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ai = "AI: " + outputs[list(outputs.keys())[0]]
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self.buffer.append("\n".join([human, ai]))
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def clear(self) -> None:
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"""Clear memory contents."""
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self.buffer = []
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class ConversationSummaryMemory(Memory, BaseModel):
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"""Conversation summarizer to memory."""
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buffer: str = ""
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llm: BaseLLM
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prompt: BasePromptTemplate = SUMMARY_PROMPT
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memory_key: str = "history" #: :meta private:
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@property
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def memory_variables(self) -> List[str]:
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"""Will always return list of memory variables.
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:meta private:
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"""
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return [self.memory_key]
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def load_memory_variables(self, inputs: Dict[str, Any]) -> Dict[str, str]:
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"""Return history buffer."""
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return {self.memory_key: self.buffer}
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@root_validator()
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def validate_prompt_input_variables(cls, values: Dict) -> Dict:
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"""Validate that prompt input variables are consistent."""
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prompt_variables = values["prompt"].input_variables
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expected_keys = {"summary", "new_lines"}
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if expected_keys != set(prompt_variables):
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raise ValueError(
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"Got unexpected prompt input variables. The prompt expects "
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f"{prompt_variables}, but it should have {expected_keys}."
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)
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return values
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def save_context(self, inputs: Dict[str, Any], outputs: Dict[str, str]) -> None:
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"""Save context from this conversation to buffer."""
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prompt_input_key = _get_prompt_input_key(inputs, self.memory_variables)
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if len(outputs) != 1:
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raise ValueError(f"One output key expected, got {outputs.keys()}")
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human = f"Human: {inputs[prompt_input_key]}"
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ai = f"AI: {list(outputs.values())[0]}"
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new_lines = "\n".join([human, ai])
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chain = LLMChain(llm=self.llm, prompt=self.prompt)
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self.buffer = chain.predict(summary=self.buffer, new_lines=new_lines)
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def clear(self) -> None:
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"""Clear memory contents."""
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self.buffer = ""
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