困惑度（Perplexity）¶

Perplexity 的 Sonar API 提供了一种将实时、基于网络的搜索与高级推理和深度研究能力相结合的解决方案。

适用场景：

• 当您的应用程序需要直接从网络获取及时、相关的数据时，例如动态内容更新或当前事件追踪。
• 适用于需要支持复杂用户查询并整合推理和深度研究功能的产品，如数字助手或高级搜索引擎。

在开始之前，请确保已安装 llama_index

In [ ]:

%pip install llama-index-llms-perplexity

%pip install llama-index-llms-perplexity

In [ ]:

!pip install llama-index

!pip install llama-index

初始设置¶

截至 2025 年 4 月 12 日，LLaMa Index 中的 Perplexity LLM 类支持以下模型：

模型	上下文长度	模型类型
sonar-deep-research	128k	聊天完成
sonar-reasoning-pro	128k	聊天完成
sonar-reasoning	128k	聊天完成
sonar-pro	200k	聊天完成
sonar	128k	聊天完成
r1-1776	128k	聊天完成

• sonar-pro 的最大输出令牌限制为 8k
• 推理模型会输出思维链（Chain of Thought）响应
• r1-1776 是离线聊天模型，不使用 Perplexity 搜索子系统

最新支持的模型列表请查阅此处
速率限制详见此处
价格信息请参考此处。

In [ ]:

import getpass
import os

if "PPLX_API_KEY" not in os.environ:
    os.environ["PPLX_API_KEY"] = getpass.getpass(
        "Enter your Perplexity API key: "
    )

import getpass import os if "PPLX_API_KEY" not in os.environ: os.environ["PPLX_API_KEY"] = getpass.getpass( "Enter your Perplexity API key: " )

In [ ]:

from llama_index.llms.perplexity import Perplexity

PPLX_API_KEY = __import__("os").environ.get("PPLX_API_KEY")

llm = Perplexity(api_key=PPLX_API_KEY, model="sonar-pro", temperature=0.2)

from llama_index.llms.perplexity import Perplexity PPLX_API_KEY = __import__("os").environ.get("PPLX_API_KEY") llm = Perplexity(api_key=PPLX_API_KEY, model="sonar-pro", temperature=0.2)

In [ ]:

# Import the ChatMessage class from the llama_index library.
from llama_index.core.llms import ChatMessage

# Create a list of dictionaries where each dictionary represents a chat message.
# Each dictionary contains a 'role' key (e.g., system or user) and a 'content' key with the corresponding message.
messages_dict = [
    {"role": "system", "content": "Be precise and concise."},
    {
        "role": "user",
        "content": "Tell me the latest news about the US Stock Market.",
    },
]

# Convert each dictionary in the list to a ChatMessage object using unpacking (**msg) in a list comprehension.
messages = [ChatMessage(**msg) for msg in messages_dict]

# Print the list of ChatMessage objects to verify the conversion.
print(messages)

# Import the ChatMessage class from the llama_index library. from llama_index.core.llms import ChatMessage # Create a list of dictionaries where each dictionary represents a chat message. # Each dictionary contains a 'role' key (e.g., system or user) and a 'content' key with the corresponding message. messages_dict = [ {"role": "system", "content": "Be precise and concise."}, { "role": "user", "content": "Tell me the latest news about the US Stock Market.", }, ] # Convert each dictionary in the list to a ChatMessage object using unpacking (**msg) in a list comprehension. messages = [ChatMessage(**msg) for msg in messages_dict] # Print the list of ChatMessage objects to verify the conversion. print(messages)

[ChatMessage(role=<MessageRole.SYSTEM: 'system'>, additional_kwargs={}, blocks=[TextBlock(block_type='text', text='Be precise and concise.')]), ChatMessage(role=<MessageRole.USER: 'user'>, additional_kwargs={}, blocks=[TextBlock(block_type='text', text='Tell me the latest news about the US Stock Market.')])]

聊天¶

In [ ]:

response = llm.chat(messages)
print(response)

response = llm.chat(messages) print(response)

assistant: The latest update on the U.S. stock market indicates a strong performance recently. A significant 10% rally occurred on Wednesday, which contributed substantially to market gains. Additionally, the market closed strongly on Friday, with a 2% increase, ending near the intraday high. This reflects robust momentum, particularly in mega and large-cap growth stocks[1].

异步聊天¶

对于异步对话处理，使用 achat 方法发送消息并等待响应：

In [ ]:

# Asynchronously send the list of chat messages to the LLM using the 'achat' method.
# This method returns a ChatResponse object containing the model's answer.
response = await llm.achat(messages)

print(response)

# Asynchronously send the list of chat messages to the LLM using the 'achat' method. # This method returns a ChatResponse object containing the model's answer. response = await llm.achat(messages) print(response)

assistant: The U.S. stock market has recently experienced significant gains. A major rally on Wednesday resulted in a 10% surge, contributing substantially to the market's overall upside. Additionally, the market closed strongly on Friday, with a 2% increase, ending near the intraday high. This performance highlights robust momentum, particularly in mega-cap and large-cap growth stocks[1].

流式聊天¶

对于需要实时逐令牌接收响应的情况，请使用 stream_chat 方法：

In [ ]:

# Call the stream_chat method on the LLM instance, which returns a generator or iterable
# for streaming the chat response one delta (token or chunk) at a time.
response = llm.stream_chat(messages)

# Iterate over each streaming response chunk.
for r in response:
    # Print the delta (the new chunk of generated text) without adding a newline.
    print(r.delta, end="")

# Call the stream_chat method on the LLM instance, which returns a generator or iterable # for streaming the chat response one delta (token or chunk) at a time. response = llm.stream_chat(messages) # Iterate over each streaming response chunk. for r in response: # Print the delta (the new chunk of generated text) without adding a newline. print(r.delta, end="")

The latest news about the U.S. stock market indicates a strong performance recently. The New York Stock Exchange (NYSE) experienced a significant rally, with a 10% surge on Wednesday, followed by a 2% gain on Friday. This upward momentum brought the market near its intraday high, driven by strength in mega-cap and large-cap growth stocks[1].

异步流式聊天¶

同样地，对于异步流式处理，astream_chat 方法提供了异步处理响应增量的方式：

In [ ]:

# Asynchronously call the astream_chat method on the LLM instance,
# which returns an asynchronous generator that yields response chunks.
resp = await llm.astream_chat(messages)

# Asynchronously iterate over each response chunk from the generator.
# For each chunk (delta), print the chunk's text content.
async for delta in resp:
    print(delta.delta, end="")

# Asynchronously call the astream_chat method on the LLM instance, # which returns an asynchronous generator that yields response chunks. resp = await llm.astream_chat(messages) # Asynchronously iterate over each response chunk from the generator. # For each chunk (delta), print the chunk's text content. async for delta in resp: print(delta.delta, end="")

The latest updates on the U.S. stock market indicate significant positive momentum. The New York Stock Exchange (NYSE) experienced a strong rally, with a notable 10% surge on Wednesday. This was followed by a 2% gain on Friday, closing near the intraday high. The market's performance has been driven by mega and large-cap growth stocks, contributing to the overall upside[1].

工具调用¶

Perplexity 模型可以轻松封装为 llamaindex 工具，从而作为数据处理或对话工作流的一部分进行调用。该工具采用 Perplexity 提供的实时生成式搜索技术，默认配置使用最新版模型（"sonar-pro"）并启用了 enable_search_classifier 参数。

以下示例展示了如何定义并注册该工具：

In [ ]:

from llama_index.core.tools import FunctionTool
from llama_index.llms.perplexity import Perplexity
from llama_index.core.llms import ChatMessage


def query_perplexity(query: str) -> str:
    """
    Queries the Perplexity API via the LlamaIndex integration.

    This function instantiates a Perplexity LLM with updated default settings
    (using model "sonar-pro" and enabling search classifier so that the API can
    intelligently decide if a search is needed), wraps the query into a ChatMessage,
    and returns the generated response content.
    """
    pplx_api_key = (
        "your-perplexity-api-key"  # Replace with your actual API key
    )

    llm = Perplexity(
        api_key=pplx_api_key,
        model="sonar-pro",
        temperature=0.7,
        enable_search_classifier=True,  # This will determine if the search component is necessary in this particular context
    )

    messages = [ChatMessage(role="user", content=query)]
    response = llm.chat(messages)
    return response.message.content


# Create the tool from the query_perplexity function
query_perplexity_tool = FunctionTool.from_defaults(fn=query_perplexity)

from llama_index.core.tools import FunctionTool from llama_index.llms.perplexity import Perplexity from llama_index.core.llms import ChatMessage def query_perplexity(query: str) -> str: """ Queries the Perplexity API via the LlamaIndex integration. This function instantiates a Perplexity LLM with updated default settings (using model "sonar-pro" and enabling search classifier so that the API can intelligently decide if a search is needed), wraps the query into a ChatMessage, and returns the generated response content. """ pplx_api_key = ( "your-perplexity-api-key" # Replace with your actual API key ) llm = Perplexity( api_key=pplx_api_key, model="sonar-pro", temperature=0.7, enable_search_classifier=True, # This will determine if the search component is necessary in this particular context ) messages = [ChatMessage(role="user", content=query)] response = llm.chat(messages) return response.message.content # Create the tool from the query_perplexity function query_perplexity_tool = FunctionTool.from_defaults(fn=query_perplexity)