langchain/templates/sql-llamacpp/sql_llamacpp/chain.py
2023-10-29 15:50:09 -07:00

137 lines
3.6 KiB
Python

# Get LLM
import os
from pathlib import Path
import requests
from langchain.llms import LlamaCpp
from langchain.memory import ConversationBufferMemory
from langchain.prompts import ChatPromptTemplate, MessagesPlaceholder
from langchain.pydantic_v1 import BaseModel
from langchain.schema.output_parser import StrOutputParser
from langchain.schema.runnable import RunnableLambda, RunnablePassthrough
from langchain.utilities import SQLDatabase
# File name and URL
file_name = "mistral-7b-instruct-v0.1.Q4_K_M.gguf"
url = (
"https://huggingface.co/TheBloke/Mistral-7B-Instruct-v0.1-GGUF/resolve/main/"
"mistral-7b-instruct-v0.1.Q4_K_M.gguf"
)
# Check if file is present in the current directory
if not os.path.exists(file_name):
print(f"'{file_name}' not found. Downloading...")
# Download the file
response = requests.get(url)
response.raise_for_status() # Raise an exception for HTTP errors
with open(file_name, "wb") as f:
f.write(response.content)
print(f"'{file_name}' has been downloaded.")
else:
print(f"'{file_name}' already exists in the current directory.")
# Add the LLM downloaded from HF
model_path = file_name
n_gpu_layers = 1 # Metal set to 1 is enough.
# Should be between 1 and n_ctx, consider the amount of RAM of your Apple Silicon Chip.
n_batch = 512
llm = LlamaCpp(
model_path=model_path,
n_gpu_layers=n_gpu_layers,
n_batch=n_batch,
n_ctx=2048,
# f16_kv MUST set to True
# otherwise you will run into problem after a couple of calls
f16_kv=True,
verbose=True,
)
db_path = Path(__file__).parent / "nba_roster.db"
rel = db_path.relative_to(Path.cwd())
db_string = f"sqlite:///{rel}"
db = SQLDatabase.from_uri(db_string, sample_rows_in_table_info=0)
def get_schema(_):
return db.get_table_info()
def run_query(query):
return db.run(query)
# Prompt
template = """Based on the table schema below, write a SQL query that would answer the user's question:
{schema}
Question: {question}
SQL Query:""" # noqa: E501
prompt = ChatPromptTemplate.from_messages(
[
("system", "Given an input question, convert it to a SQL query. No pre-amble."),
MessagesPlaceholder(variable_name="history"),
("human", template),
]
)
memory = ConversationBufferMemory(return_messages=True)
# Chain to query with memory
sql_chain = (
RunnablePassthrough.assign(
schema=get_schema,
history=RunnableLambda(lambda x: memory.load_memory_variables(x)["history"]),
)
| prompt
| llm.bind(stop=["\nSQLResult:"])
| StrOutputParser()
)
def save(input_output):
output = {"output": input_output.pop("output")}
memory.save_context(input_output, output)
return output["output"]
sql_response_memory = RunnablePassthrough.assign(output=sql_chain) | save
# Chain to answer
template = """Based on the table schema below, question, sql query, and sql response, write a natural language response:
{schema}
Question: {question}
SQL Query: {query}
SQL Response: {response}""" # noqa: E501
prompt_response = ChatPromptTemplate.from_messages(
[
(
"system",
"Given an input question and SQL response, convert it to a natural "
"language answer. No pre-amble.",
),
("human", template),
]
)
# Supply the input types to the prompt
class InputType(BaseModel):
question: str
chain = (
RunnablePassthrough.assign(query=sql_response_memory).with_types(
input_type=InputType
)
| RunnablePassthrough.assign(
schema=get_schema,
response=lambda x: db.run(x["query"]),
)
| prompt_response
| llm
)