"""Wrapper for the GPT4All model."""
from functools import partial
from typing import Any, Dict, List, Mapping, Optional, Set
from pydantic import Extra, Field, root_validator
from langchain.llms.base import LLM
from langchain.llms.utils import enforce_stop_tokens
[docs]class GPT4All(LLM):
r"""Wrapper around GPT4All language models.
To use, you should have the ``pyllamacpp`` python package installed, the
pre-trained model file, and the model's config information.
Example:
.. code-block:: python
from langchain.llms import GPT4All
model = GPT4All(model="./models/gpt4all-model.bin", n_ctx=512, n_threads=8)
# Simplest invocation
response = model("Once upon a time, ")
"""
model: str
"""Path to the pre-trained GPT4All model file."""
n_ctx: int = Field(512, alias="n_ctx")
"""Token context window."""
n_parts: int = Field(-1, alias="n_parts")
"""Number of parts to split the model into.
If -1, the number of parts is automatically determined."""
seed: int = Field(0, alias="seed")
"""Seed. If -1, a random seed is used."""
f16_kv: bool = Field(False, alias="f16_kv")
"""Use half-precision for key/value cache."""
logits_all: bool = Field(False, alias="logits_all")
"""Return logits for all tokens, not just the last token."""
vocab_only: bool = Field(False, alias="vocab_only")
"""Only load the vocabulary, no weights."""
use_mlock: bool = Field(False, alias="use_mlock")
"""Force system to keep model in RAM."""
embedding: bool = Field(False, alias="embedding")
"""Use embedding mode only."""
n_threads: Optional[int] = Field(4, alias="n_threads")
"""Number of threads to use."""
n_predict: Optional[int] = 256
"""The maximum number of tokens to generate."""
temp: Optional[float] = 0.8
"""The temperature to use for sampling."""
top_p: Optional[float] = 0.95
"""The top-p value to use for sampling."""
top_k: Optional[int] = 40
"""The top-k value to use for sampling."""
echo: Optional[bool] = False
"""Whether to echo the prompt."""
stop: Optional[List[str]] = []
"""A list of strings to stop generation when encountered."""
repeat_last_n: Optional[int] = 64
"Last n tokens to penalize"
repeat_penalty: Optional[float] = 1.3
"""The penalty to apply to repeated tokens."""
n_batch: int = Field(1, alias="n_batch")
"""Batch size for prompt processing."""
streaming: bool = False
"""Whether to stream the results or not."""
client: Any = None #: :meta private:
class Config:
"""Configuration for this pydantic object."""
extra = Extra.forbid
@property
def _default_params(self) -> Dict[str, Any]:
"""Get the identifying parameters."""
return {
"seed": self.seed,
"n_predict": self.n_predict,
"n_threads": self.n_threads,
"n_batch": self.n_batch,
"repeat_last_n": self.repeat_last_n,
"repeat_penalty": self.repeat_penalty,
"top_k": self.top_k,
"top_p": self.top_p,
"temp": self.temp,
}
@staticmethod
def _llama_param_names() -> Set[str]:
"""Get the identifying parameters."""
return {
"seed",
"n_ctx",
"n_parts",
"f16_kv",
"logits_all",
"vocab_only",
"use_mlock",
"embedding",
}
@root_validator()
def validate_environment(cls, values: Dict) -> Dict:
"""Validate that the python package exists in the environment."""
try:
from pyllamacpp.model import Model as GPT4AllModel
llama_keys = cls._llama_param_names()
model_kwargs = {k: v for k, v in values.items() if k in llama_keys}
values["client"] = GPT4AllModel(
ggml_model=values["model"],
**model_kwargs,
)
except ImportError:
raise ValueError(
"Could not import pyllamacpp python package. "
"Please install it with `pip install pyllamacpp`."
)
return values
@property
def _identifying_params(self) -> Mapping[str, Any]:
"""Get the identifying parameters."""
return {
"model": self.model,
**self._default_params,
**{
k: v
for k, v in self.__dict__.items()
if k in GPT4All._llama_param_names()
},
}
@property
def _llm_type(self) -> str:
"""Return the type of llm."""
return "gpt4all"
def _call(self, prompt: str, stop: Optional[List[str]] = None) -> str:
r"""Call out to GPT4All's generate method.
Args:
prompt: The prompt to pass into the model.
stop: A list of strings to stop generation when encountered.
Returns:
The string generated by the model.
Example:
.. code-block:: python
prompt = "Once upon a time, "
response = model(prompt, n_predict=55)
"""
text_callback = partial(
self.callback_manager.on_llm_new_token, verbose=self.verbose
)
text = self.client.generate(
prompt,
new_text_callback=text_callback,
**self._default_params,
)
if stop is not None:
text = enforce_stop_tokens(text, stop)
return text