LLMRequestsChain
使用请求库从URL获取HTML结果，然后使用LLM解析结果
from langchain.llms import OpenAI
from langchain.chains import LLMRequestsChain, LLMChain定义使用的提示：
from langchain.prompts import PromptTemplate
template = """Between >>> and <<< are the raw search result text from google.
Extract the answer to the question '{query}' or say "not found" if the information is not contained.
Use the format
Extracted:<answer or "not found">
>>> {requests_result} <<<
Extracted:"""
PROMPT = PromptTemplate(
input_variables=["query", "requests_result"],
template=template,
)实例化LLMRequestsChain：
chain = LLMRequestsChain(llm_chain = LLMChain(llm=OpenAI(temperature=0), prompt=PROMPT))定义输入：
question = "What are the Three (3) biggest countries, and their respective sizes?"
inputs = {
"query": question,
"url": "https://www.google.com/search?q=" + question.replace(" ", "+")
}运行LLMRequestsChain：
chain(inputs)输出如下：
{'query': 'What are the Three (3) biggest countries, and their respective sizes?',
'url': 'https://www.google.com/search?q=What+are+the+Three+(3)+biggest+countries,+and+their+respective+sizes?',
'output': '俄罗斯(17,098,242平方公里)，加拿大(9,984,670平方公里)，美国(9,826,675平方公里)'}