chatAlpaca / app.py
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Streamlit chat
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"""Python file to serve as the frontend"""
import streamlit as st
from streamlit_chat import message
from langchain.chains import ConversationChain, LLMChain
from langchain import PromptTemplate
from langchain.llms.base import LLM
from langchain.memory import ConversationBufferWindowMemory
from typing import Optional, List, Mapping, Any
import torch
from peft import PeftModel
import transformers
from transformers import LlamaTokenizer, LlamaForCausalLM, GenerationConfig
from transformers import BitsAndBytesConfig
tokenizer = LlamaTokenizer.from_pretrained("decapoda-research/llama-7b-hf")
quantization_config = BitsAndBytesConfig(llm_int8_enable_fp32_cpu_offload=True)
model = LlamaForCausalLM.from_pretrained(
"decapoda-research/llama-7b-hf",
# load_in_8bit=True,
# torch_dtype=torch.float16,
device_map="auto",
# device_map={"":"cpu"},
max_memory={"cpu":"15GiB"}
quantization_config=quantization_config
)
model = PeftModel.from_pretrained(
model, "tloen/alpaca-lora-7b",
# torch_dtype=torch.float16,
device_map={"":"cpu"},
)
device = "cpu"
print("model device :", model.device, flush=True)
# model.to(device)
model.eval()
def evaluate_raw_prompt(
prompt:str,
temperature=0.1,
top_p=0.75,
top_k=40,
num_beams=4,
**kwargs,
):
inputs = tokenizer(prompt, return_tensors="pt")
input_ids = inputs["input_ids"].to(device)
generation_config = GenerationConfig(
temperature=temperature,
top_p=top_p,
top_k=top_k,
num_beams=num_beams,
**kwargs,
)
with torch.no_grad():
generation_output = model.generate(
input_ids=input_ids,
generation_config=generation_config,
return_dict_in_generate=True,
output_scores=True,
max_new_tokens=256,
)
s = generation_output.sequences[0]
output = tokenizer.decode(s)
# return output
return output.split("### Response:")[1].strip()
class AlpacaLLM(LLM):
temperature: float
top_p: float
top_k: int
num_beams: int
@property
def _llm_type(self) -> str:
return "custom"
def _call(self, prompt: str, stop: Optional[List[str]] = None) -> str:
if stop is not None:
raise ValueError("stop kwargs are not permitted.")
answer = evaluate_raw_prompt(prompt,
top_p= self.top_p,
top_k= self.top_k,
num_beams= self.num_beams,
temperature= self.temperature
)
return answer
@property
def _identifying_params(self) -> Mapping[str, Any]:
"""Get the identifying parameters."""
return {
"top_p": self.top_p,
"top_k": self.top_k,
"num_beams": self.num_beams,
"temperature": self.temperature
}
template = """Below is an instruction that describes a task, paired with an input that provides further context. Write a response that appropriately completes the request.
### Instruction:
You are a chatbot, you should answer my last question very briefly. You are consistent and non repetitive.
### Chat:
{history}
Human: {human_input}
### Response:"""
prompt = PromptTemplate(
input_variables=["history","human_input"],
template=template,
)
def load_chain():
"""Logic for loading the chain you want to use should go here."""
llm = AlpacaLLM(top_p=0.75, top_k=40, num_beams=4, temperature=0.1)
# chain = ConversationChain(llm=llm)
chain = LLMChain(llm=llm, prompt=prompt, memory=ConversationBufferWindowMemory(k=2))
return chain
chain = load_chain()
# # From here down is all the StreamLit UI.
# st.set_page_config(page_title="LangChain Demo", page_icon=":robot:")
# st.header("LangChain Demo")
# if "generated" not in st.session_state:
# st.session_state["generated"] = []
# if "past" not in st.session_state:
# st.session_state["past"] = []
# def get_text():
# input_text = st.text_input("Human: ", "Hello, how are you?", key="input")
# return input_text
# user_input = get_text()
# if user_input:
# output = chain.predict(human_input=user_input)
# st.session_state.past.append(user_input)
# st.session_state.generated.append(output)
# if st.session_state["generated"]:
# for i in range(len(st.session_state["generated"]) - 1, -1, -1):
# message(st.session_state["generated"][i], key=str(i))
# message(st.session_state["past"][i], is_user=True, key=str(i) + "_user")
st.title("ChatAlpaca")
if "history" not in st.session_state:
st.session_state.history = []
st.session_state.history.append({"message": "Hey, I'm a Alpaca chatBot. Ask whatever you want!", "is_user": False})
def generate_answer():
user_message = st.session_state.input_text
inputs = tokenizer(st.session_state.input_text, return_tensors="pt")
result = model.generate(**inputs)
message_bot = tokenizer.decode(result[0], skip_special_tokens=True) # .replace("<s>", "").replace("</s>", "")
st.session_state.history.append({"message": user_message, "is_user": True})
st.session_state.history.append({"message": message_bot, "is_user": False})
st.text_input("Response", key="input_text", on_change=generate_answer)
for chat in st.session_state.history:
st_message(**chat)