Langchain开发环境部署及使用本地模型详解

python -m venv myLC

cd C:\Users\amdin
myLC\Scripts\activate

pip install langchain langchain-openai langchain-core langchain-community -i https://mirrors.tuna.tsinghua.edu.cn/pypi/web/simple

pip install tiktoken chromadb faiss-cpu python-dotenv -i https://mirrors.tuna.tsinghua.edu.cn/pypi/web/simple

import sys
import langchain
import openai

# 打印已安装库的版本
print(f"LangChain version: {langchain.__version__}")
print(f"OpenAI version: {openai.__version__}")

# 打印 Python 解释器版本
print(f"Python version: {sys.version}")

python -m vllm.entrypoints.openai.api_server --model modelpath --host 0.0.0.0 --port 18000 --served-model-name deepseek-r1-local

from langchain_openai import ChatOpenAI
# --- core cfg ---
# User ChatOpenAI Class obj，and configure it to point to DeepSeek's API
# 1. model_name:  DeepSeek model name，
# 2. openai_api_base: DeepSeek API point，default is https://api.deepseek.com
# 3. openai_api_key: local mode need to set it to "none"
# 4. max_tokens: max token num
llm = ChatOpenAI(    
model_name="deepseek-r1-localg",      
openai_api_base="http://127.0.0.1:18000/v1/",    
openai_api_key="none",      
max_tokens=1024,    
temperature=0.7
)
try:    
print("Calling local DeepSeek-R1 model...")    
response = llm.invoke("who are you ? and explain how you differ from OpenAI's GPT model?")        
print("\n--- Local DeepSeek-R1 answer ---")    
print(response.content)    
print("------------------------")
except Exception as e:    
print(f"Error: {e}")