Langchain-Chatchat/knowledge_based_chatglm.py

125 lines
4.2 KiB
Python

from langchain.chains import RetrievalQA
from langchain.prompts import PromptTemplate
from langchain.embeddings.huggingface import HuggingFaceEmbeddings
from langchain.vectorstores import FAISS
from langchain.document_loaders import UnstructuredFileLoader
from chatglm_llm import ChatGLM
import sentence_transformers
import torch
import os
import readline
# Global Parameters
EMBEDDING_MODEL = "text2vec"
VECTOR_SEARCH_TOP_K = 6
LLM_MODEL = "chatglm-6b"
LLM_HISTORY_LEN = 3
DEVICE = "cuda" if torch.cuda.is_available() else "mps" if torch.backends.mps.is_available() else "cpu"
# Show reply with source text from input document
REPLY_WITH_SOURCE = True
embedding_model_dict = {
"ernie-tiny": "nghuyong/ernie-3.0-nano-zh",
"ernie-base": "nghuyong/ernie-3.0-base-zh",
"text2vec": "GanymedeNil/text2vec-large-chinese",
}
llm_model_dict = {
"chatglm-6b-int4-qe": "THUDM/chatglm-6b-int4-qe",
"chatglm-6b-int4": "THUDM/chatglm-6b-int4",
"chatglm-6b": "THUDM/chatglm-6b",
}
def init_cfg(LLM_MODEL, EMBEDDING_MODEL, LLM_HISTORY_LEN, V_SEARCH_TOP_K=6):
global chatglm, embeddings, VECTOR_SEARCH_TOP_K
VECTOR_SEARCH_TOP_K = V_SEARCH_TOP_K
chatglm = ChatGLM()
chatglm.load_model(model_name_or_path=llm_model_dict[LLM_MODEL])
chatglm.history_len = LLM_HISTORY_LEN
embeddings = HuggingFaceEmbeddings(model_name=embedding_model_dict[EMBEDDING_MODEL],)
embeddings.client = sentence_transformers.SentenceTransformer(embeddings.model_name,
device=DEVICE)
def init_knowledge_vector_store(filepath:str):
if not os.path.exists(filepath):
print("路径不存在")
return None
elif os.path.isfile(filepath):
file = os.path.split(filepath)[-1]
try:
loader = UnstructuredFileLoader(filepath, mode="elements")
docs = loader.load()
print(f"{file} 已成功加载")
except:
print(f"{file} 未能成功加载")
return None
elif os.path.isdir(filepath):
docs = []
for file in os.listdir(filepath):
fullfilepath = os.path.join(filepath, file)
try:
loader = UnstructuredFileLoader(fullfilepath, mode="elements")
docs += loader.load()
print(f"{file} 已成功加载")
except:
print(f"{file} 未能成功加载")
vector_store = FAISS.from_documents(docs, embeddings)
return vector_store
def get_knowledge_based_answer(query, vector_store, chat_history=[]):
global chatglm, embeddings
prompt_template = """基于以下已知信息,简洁和专业的来回答用户的问题。
如果无法从中得到答案,请说 "根据已知信息无法回答该问题""没有提供足够的相关信息",不允许在答案中添加编造成分,答案请使用中文。
已知内容:
{context}
问题:
{question}"""
prompt = PromptTemplate(
template=prompt_template,
input_variables=["context", "question"]
)
chatglm.history = chat_history
knowledge_chain = RetrievalQA.from_llm(
llm=chatglm,
retriever=vector_store.as_retriever(search_kwargs={"k": VECTOR_SEARCH_TOP_K}),
prompt=prompt
)
knowledge_chain.combine_documents_chain.document_prompt = PromptTemplate(
input_variables=["page_content"], template="{page_content}"
)
knowledge_chain.return_source_documents = True
result = knowledge_chain({"query": query})
chatglm.history[-1][0] = query
return result, chatglm.history
if __name__ == "__main__":
init_cfg(LLM_MODEL, EMBEDDING_MODEL, LLM_HISTORY_LEN)
vector_store = None
while not vector_store:
filepath = input("Input your local knowledge file path 请输入本地知识文件路径:")
vector_store = init_knowledge_vector_store(filepath)
history = []
while True:
query = input("Input your question 请输入问题:")
resp, history = get_knowledge_based_answer(query=query,
vector_store=vector_store,
chat_history=history)
if REPLY_WITH_SOURCE:
print(resp)
else:
print(resp["result"])