Vertex AI

注意： Vertex 已基本被 Google GenAI 取代，后者通过 google-genai 包支持与 Vertex 相同的功能。请访问 Google GenAI 页面获取最新示例和文档。

安装 Vertex AI

要安装 Vertex AI，您需要按照以下步骤操作

安装 Vertex Cloud SDK (https://googleapis.dev/python/aiplatform/latest/index.html)
设置您的默认项目、凭据和区域

服务账户的基础认证示例

%pip install llama-index-llms-vertex

from llama_index.llms.vertex import Vertex
from google.oauth2 import service_account

filename = "vertex-407108-37495ce6c303.json"
credentials: service_account.Credentials = (
    service_account.Credentials.from_service_account_file(filename)
)
Vertex(
    model="text-bison", project=credentials.project_id, credentials=credentials
)

基本用法

对 text-bison 模型的基础调用

from llama_index.llms.vertex import Vertex
from llama_index.core.llms import ChatMessage, MessageRole

llm = Vertex(model="text-bison", temperature=0, additional_kwargs={})
llm.complete("Hello this is a sample text").text

' ```\nHello this is a sample text\n```'

异步使用

异步

(await llm.acomplete("hello")).text

' Hello! How can I help you?'

流式使用

流式处理

list(llm.stream_complete("hello"))[-1].text

' Hello! How can I help you?'

聊天使用

聊天生成

chat = Vertex(model="chat-bison")
messages = [
    ChatMessage(role=MessageRole.SYSTEM, content="Reply everything in french"),
    ChatMessage(role=MessageRole.USER, content="Hello"),
]

chat.chat(messages=messages).message.content

' Bonjour! Comment vas-tu?'

异步聊天

异步聊天响应

(await chat.achat(messages=messages)).message.content

' Bonjour! Comment vas-tu?'

流式聊天

流式聊天响应

list(chat.stream_chat(messages=messages))[-1].message.content

' Bonjour! Comment vas-tu?'

Gemini 模型

通过 Vertex AI 调用 Google Gemini 模型已获得完整支持。

Gemini Pro

llm = Vertex(
    model="gemini-pro",
    project=credentials.project_id,
    credentials=credentials,
    context_window=100000,
)
llm.complete("Hello Gemini").text

Gemini 视觉模型

Gemini视觉模型现在支持TextBlock和ImageBlock用于结构化多模态输入，取代了旧有的基于字典的content格式。使用blocks可通过文件路径或URL包含文本和图像。

图像路径示例：

from llama_index.llms.vertex import Vertex
from llama_index.core.llms import ChatMessage, TextBlock, ImageBlock

history = [
    ChatMessage(
        role="user",
        blocks=[
            ImageBlock(path="sample.jpg"),
            TextBlock(text="What is in this image?"),
        ],
    ),
]
llm = Vertex(
    model="gemini-1.5-flash",
    project=credentials.project_id,
    credentials=credentials,
    context_window=100000,
)
print(llm.chat(history).message.content)

The image shows a man in handcuffs being escorted by police officers. The man is wearing a black jacket and a black hooded sweatshirt. He is being escorted by two police officers who are wearing black balaclavas and bulletproof vests. The officers are from the Romanian Gendarmerie. The image is likely from a news report or a documentary about a crime.

图像URL示例：

from llama_index.llms.vertex import Vertex
from llama_index.core.llms import ChatMessage, TextBlock, ImageBlock

history = [
    ChatMessage(
        role="user",
        blocks=[
            ImageBlock(
                url="https://upload.wikimedia.org/wikipedia/commons/7/71/Sibirischer_tiger_de_edit02.jpg"
            ),
            TextBlock(text="What is in this image?"),
        ],
    ),
]
llm = Vertex(
    model="gemini-1.5-flash",
    project=credentials.project_id,
    credentials=credentials,
    context_window=100000,
)
print(llm.chat(history).message.content)

A close-up of a tiger's face. The tiger is looking directly at the camera with a serious expression. The fur is a mix of orange, black, and white. The background is blurred, making the tiger the main focus of the image.