PlayWright 浏览器工具包集成

使用 LangChain Python 与 PlayWright 浏览器工具包集成。

Playwright 是由 Microsoft 开发的开源自动化工具，允许您通过编程方式控制和自动化 Web 浏览器。它旨在用于端到端测试、数据抓取以及在各种 Web 浏览器（如 Chromium、Firefox 和 WebKit）上自动化任务。

此工具包用于与浏览器交互。虽然其他工具（如 Requests 工具）适用于静态站点，但 PlayWright Browser 工具包可以让您的代理浏览网页并与动态渲染的站点进行交互。

PlayWright Browser 工具包中包含的一些工具包括：

• NavigateTool (navigate_browser) - 导航到 URL
• NavigateBackTool (previous_page) - 等待元素出现
• ClickTool (click_element) - 点击元素（由选择器指定）
• ExtractTextTool (extract_text) - 使用 beautiful soup 从当前网页提取文本
• ExtractHyperlinksTool (extract_hyperlinks) - 使用 beautiful soup 从当前网页提取超链接
• GetElementsTool (get_elements) - 按 CSS 选择器选择元素
• CurrentPageTool (current_page) - 获取当前页面 URL

pip install -qU  playwright > /dev/null
pip install -qU  lxml

# If this is your first time using playwright, you'll have to install a browser executable.
# Running `playwright install` by default installs a chromium browser executable.
# playwright install

from langchain_community.agent_toolkits import PlayWrightBrowserToolkit

Async function to create context and launch browser:

from langchain_community.tools.playwright.utils import (
    create_async_playwright_browser,  # A synchronous browser is available, though it isn't compatible with jupyter.\n",   },
)

# This import is required only for jupyter notebooks, since they have their own eventloop
import nest_asyncio

nest_asyncio.apply()

实例化浏览器工具包

始终建议使用 from_browser 方法进行实例化，以便正确初始化和管理浏览器上下文，确保无缝交互和资源优化。

async_browser = create_async_playwright_browser()
toolkit = PlayWrightBrowserToolkit.from_browser(async_browser=async_browser)
tools = toolkit.get_tools()
tools

[ClickTool(async_browser=<Browser type=<BrowserType name=chromium executable_path=/Users/isaachershenson/Library/Caches/ms-playwright/chromium-1124/chrome-mac/Chromium.app/Contents/MacOS/Chromium> version=127.0.6533.17>),
 NavigateTool(async_browser=<Browser type=<BrowserType name=chromium executable_path=/Users/isaachershenson/Library/Caches/ms-playwright/chromium-1124/chrome-mac/Chromium.app/Contents/MacOS/Chromium> version=127.0.6533.17>),
 NavigateBackTool(async_browser=<Browser type=<BrowserType name=chromium executable_path=/Users/isaachershenson/Library/Caches/ms-playwright/chromium-1124/chrome-mac/Chromium.app/Contents/MacOS/Chromium> version=127.0.6533.17>),
 ExtractTextTool(async_browser=<Browser type=<BrowserType name=chromium executable_path=/Users/isaachershenson/Library/Caches/ms-playwright/chromium-1124/chrome-mac/Chromium.app/Contents/MacOS/Chromium> version=127.0.6533.17>),
 ExtractHyperlinksTool(async_browser=<Browser type=<BrowserType name=chromium executable_path=/Users/isaachershenson/Library/Caches/ms-playwright/chromium-1124/chrome-mac/Chromium.app/Contents/MacOS/Chromium> version=127.0.6533.17>),
 GetElementsTool(async_browser=<Browser type=<BrowserType name=chromium executable_path=/Users/isaachershenson/Library/Caches/ms-playwright/chromium-1124/chrome-mac/Chromium.app/Contents/MacOS/Chromium> version=127.0.6533.17>),
 CurrentWebPageTool(async_browser=<Browser type=<BrowserType name=chromium executable_path=/Users/isaachershenson/Library/Caches/ms-playwright/chromium-1124/chrome-mac/Chromium.app/Contents/MacOS/Chromium> version=127.0.6533.17>)]

tools_by_name = {tool.name: tool for tool in tools}
navigate_tool = tools_by_name["navigate_browser"]
get_elements_tool = tools_by_name["get_elements"]

await navigate_tool.arun(
    {"url": "https://web.archive.org/web/20230428133211/https://cnn.com/world"}
)

'Navigating to https://web.archive.org/web/20230428133211/https://cnn.com/world returned status code 200'

# The browser is shared across tools, so the agent can interact in a stateful manner
await get_elements_tool.arun(
    {"selector": ".container__headline", "attributes": ["innerText"]}
)

'[{"innerText": "These Ukrainian veterinarians are risking their lives to care for dogs and cats in the war zone"}, {"innerText": "Life in the ocean’s ‘twilight zone’ could disappear due to the climate crisis"}, {"innerText": "Clashes renew in West Darfur as food and water shortages worsen in Sudan violence"}, {"innerText": "Thai policeman’s wife investigated over alleged murder and a dozen other poison cases"}, {"innerText": "American teacher escaped Sudan on French evacuation plane, with no help offered back home"}, {"innerText": "Dubai’s emerging hip-hop scene is finding its voice"}, {"innerText": "How an underwater film inspired a marine protected area off Kenya’s coast"}, {"innerText": "The Iranian drones deployed by Russia in Ukraine are powered by stolen Western technology, research reveals"}, {"innerText": "India says border violations erode ‘entire basis’ of ties with China"}, {"innerText": "Australian police sift through 3,000 tons of trash for missing woman’s remains"}, {"innerText": "As US and Philippine defense ties grow, China warns over Taiwan tensions"}, {"innerText": "Don McLean offers duet with South Korean president who sang ‘American Pie’ to Biden"}, {"innerText": "Almost two-thirds of elephant habitat lost across Asia, study finds"}, {"innerText": "‘We don’t sleep … I would call it fainting’: Working as a doctor in Sudan’s crisis"}, {"innerText": "Kenya arrests second pastor to face criminal charges ‘related to mass killing of his followers’"}, {"innerText": "Russia launches deadly wave of strikes across Ukraine"}, {"innerText": "Woman forced to leave her forever home or ‘walk to your death’ she says"}, {"innerText": "U.S. House Speaker Kevin McCarthy weighs in on Disney-DeSantis feud"}, {"innerText": "Two sides agree to extend Sudan ceasefire"}, {"innerText": "Spanish Leopard 2 tanks are on their way to Ukraine, defense minister confirms"}, {"innerText": "Flambéed pizza thought to have sparked deadly Madrid restaurant fire"}, {"innerText": "Another bomb found in Belgorod just days after Russia accidentally struck the city"}, {"innerText": "A Black teen’s murder sparked a crisis over racism in British policing. Thirty years on, little has changed"}, {"innerText": "Belgium destroys shipment of American beer after taking issue with ‘Champagne of Beer’ slogan"}, {"innerText": "UK Prime Minister Rishi Sunak rocked by resignation of top ally Raab over bullying allegations"}, {"innerText": "Iran’s Navy seizes Marshall Islands-flagged ship"}, {"innerText": "A divided Israel stands at a perilous crossroads on its 75th birthday"}, {"innerText": "Palestinian reporter breaks barriers by reporting in Hebrew on Israeli TV"}, {"innerText": "One-fifth of water pollution comes from textile dyes. But a shellfish-inspired solution could clean it up"}, {"innerText": "‘People sacrificed their lives for just\xa010 dollars’: At least 78 killed in Yemen crowd surge"}, {"innerText": "Israeli police say two men shot near Jewish tomb in Jerusalem in suspected ‘terror attack’"}, {"innerText": "King Charles III’s coronation: Who’s performing at the ceremony"}, {"innerText": "The week in 33 photos"}, {"innerText": "Hong Kong’s endangered turtles"}, {"innerText": "In pictures: Britain’s Queen Camilla"}, {"innerText": "Catastrophic drought that’s pushed millions into crisis made 100 times more likely by climate change, analysis finds"}, {"innerText": "For years, a UK mining giant was untouchable in Zambia for pollution until a former miner’s son took them on"}, {"innerText": "Former Sudanese minister Ahmed Haroun wanted on war crimes charges freed from Khartoum prison"}, {"innerText": "WHO warns of ‘biological risk’ after Sudan fighters seize lab, as violence mars US-brokered ceasefire"}, {"innerText": "How Colombia’s Petro, a former leftwing guerrilla, found his opening in Washington"}, {"innerText": "Bolsonaro accidentally created Facebook post questioning Brazil election results, say his attorneys"}, {"innerText": "Crowd kills over a dozen suspected gang members in Haiti"}, {"innerText": "Thousands of tequila bottles containing liquid meth seized"}, {"innerText": "Why send a US stealth submarine to South Korea – and tell the world about it?"}, {"innerText": "Fukushima’s fishing industry survived a nuclear disaster. 12 years on, it fears Tokyo’s next move may finish it off"}, {"innerText": "Singapore executes man for trafficking two pounds of cannabis"}, {"innerText": "Conservative Thai party looks to woo voters with promise to legalize sex toys"}, {"innerText": "Inside the Italian village being repopulated by Americans"}, {"innerText": "Strikes, soaring airfares and yo-yoing hotel fees: A traveler’s guide to the coronation"}, {"innerText": "A year in Azerbaijan: From spring’s Grand Prix to winter ski adventures"}, {"innerText": "The bicycle mayor peddling a two-wheeled revolution in Cape Town"}, {"innerText": "Tokyo ramen shop bans customers from using their phones while eating"}, {"innerText": "South African opera star will perform at coronation of King Charles III"}, {"innerText": "Luxury loot under the hammer: France auctions goods seized from drug dealers"}, {"innerText": "Judy Blume’s books were formative for generations of readers. Here’s why they endure"}, {"innerText": "Craft, salvage and sustainability take center stage at Milan Design Week"}, {"innerText": "Life-sized chocolate King Charles III sculpture unveiled to celebrate coronation"}, {"innerText": "Severe storms to strike the South again as millions in Texas could see damaging winds and hail"}, {"innerText": "The South is in the crosshairs of severe weather again, as the multi-day threat of large hail and tornadoes continues"}, {"innerText": "Spring snowmelt has cities along the Mississippi bracing for flooding in homes and businesses"}, {"innerText": "Know the difference between a tornado watch, a tornado warning and a tornado emergency"}, {"innerText": "Reporter spotted familiar face covering Sudan evacuation. See what happened next"}, {"innerText": "This country will soon become the world’s most populated"}, {"innerText": "April 27, 2023 - Russia-Ukraine news"}, {"innerText": "‘Often they shoot at each other’: Ukrainian drone operator details chaos in Russian ranks"}, {"innerText": "Hear from family members of Americans stuck in Sudan frustrated with US response"}, {"innerText": "U.S. talk show host Jerry Springer dies at 79"}, {"innerText": "Bureaucracy stalling at least one family’s evacuation from Sudan"}, {"innerText": "Girl to get life-saving treatment for rare immune disease"}, {"innerText": "Haiti’s crime rate more than doubles in a year"}, {"innerText": "Ocean census aims to discover 100,000 previously unknown marine species"}, {"innerText": "Wall Street Journal editor discusses reporter’s arrest in Moscow"}, {"innerText": "Can Tunisia’s democracy be saved?"}, {"innerText": "Yasmeen Lari, ‘starchitect’ turned social engineer, wins one of architecture’s most coveted prizes"}, {"innerText": "A massive, newly restored Frank Lloyd Wright mansion is up for sale"}, {"innerText": "Are these the most sustainable architectural projects in the world?"}, {"innerText": "Step inside a $72 million London townhouse in a converted army barracks"}, {"innerText": "A 3D-printing company is preparing to build on the lunar surface. But first, a moonshot at home"}, {"innerText": "Simona Halep says ‘the stress is huge’ as she battles to return to tennis following positive drug test"}, {"innerText": "Barcelona reaches third straight Women’s Champions League final with draw against Chelsea"}, {"innerText": "Wrexham: An intoxicating tale of Hollywood glamor and sporting romance"}, {"innerText": "Shohei Ohtani comes within inches of making yet more MLB history in Angels win"}, {"innerText": "This CNN Hero is recruiting recreational divers to help rebuild reefs in Florida one coral at a time"}, {"innerText": "This CNN Hero offers judgment-free veterinary care for the pets of those experiencing homelessness"}, {"innerText": "Don’t give up on milestones: A CNN Hero’s message for Autism Awareness Month"}, {"innerText": "CNN Hero of the Year Nelly Cheboi returned to Kenya with plans to lift more students out of poverty"}]'

# If the agent wants to remember the current webpage, it can use the `current_webpage` tool
await tools_by_name["current_webpage"].arun({})

'https://web.archive.org/web/20230428133211/https://cnn.com/world'

在 Agent 中使用

其中几个浏览器工具是 StructuredTool，意味着它们需要多个参数。这些工具与早于 STRUCTURED_CHAT_ZERO_SHOT_REACT_DESCRIPTION 的代理不兼容（开箱即用）。

from langchain_anthropic import ChatAnthropic
from langchain.agents import create_agent


model = ChatAnthropic(
    model_name="claude-haiku-4-5-20251001", temperature=0
)  # or any other LLM, e.g., ChatOpenAI(), OpenAI()

agent_chain = create_agent(model=model, tools=tools)

result = await agent_chain.ainvoke(
    {"messages": [("user", "What are the headers on langchain.com?")]}
)
print(result)

> Entering new AgentExecutor chain...
Thought: To find the headers on langchain.com, I will navigate to the website and extract the text.

Action:
\`\`\`
{
  "action": "navigate_browser",
  "action_input": "https://langchain.com"
}
\`\`\`


Observation: Navigating to https://langchain.com returned status code 200
Thought:Okay, let's find the headers on the langchain.com website.

Action:
\`\`\`
{
  "action": "extract_text",
  "action_input": {}
}
\`\`\`


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Reject All Save My Preferences Accept All Products LangChain LangSmith LangGraph Methods Retrieval Agents Evaluation Resources Blog Case Studies Use Case Inspiration Experts Changelog Docs LangChain Docs LangSmith Docs Company About Careers Pricing Get a demo Sign up LangChain’s suite of products supports developers along each step of the LLM application lifecycle. Applications that can reason. Powered by LangChain. Get a demo Sign up for free From startups to global enterprises, ambitious builders choose LangChain products. Build LangChain is a framework to build with LLMs by chaining interoperable components. LangGraph is the framework for building controllable agentic workflows. Run Deploy your LLM applications at scale with LangGraph Cloud, our infrastructure purpose-built for agents. Manage Debug, collaborate, test, and monitor your LLM app in LangSmith - whether it's built with a LangChain framework or not. 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Thought:Based on the text extracted from the langchain.com website, the main headers I can see are:

- LangChain
- Products
  - LangChain
  - LangSmith
  - LangGraph
- Methods
  - Retrieval
  - Agents
  - Evaluation
- Resources
  - Blog
  - Case Studies
  - Use Case Inspiration
  - Experts
  - Changelog
- Docs
  - LangChain Docs
  - LangSmith Docs
- Company
  - About
  - Careers
  - Pricing
- Get a demo
- Sign up

The website appears to be organized around their main product offerings (LangChain, LangSmith, LangGraph) as well as resources and documentation.

Action:
\`\`\`
{
  "action": "Final Answer",
  "action_input": "The main headers on the langchain.com website are:\n\n- LangChain\n- Products\n  - LangChain\n  - LangSmith\n  - LangGraph\n- Methods\n  - Retrieval\n  - Agents\n  - Evaluation\n- Resources\n  - Blog\n  - Case Studies\n  - Use Case Inspiration\n  - Experts\n  - Changelog\n- Docs\n  - LangChain Docs\n  - LangSmith Docs\n- Company\n  - About\n  - Careers\n  - Pricing\n- Get a demo\n- Sign up"
}
\`\`\`

> Finished chain.
The main headers on the langchain.com website are:

- LangChain
- Products
  - LangChain
  - LangSmith
  - LangGraph
- Methods
  - Retrieval
  - Agents
  - Evaluation
- Resources
  - Blog
  - Case Studies
  - Use Case Inspiration
  - Experts
  - Changelog
- Docs
  - LangChain Docs
  - LangSmith Docs
- Company
  - About
  - Careers
  - Pricing
- Get a demo
- Sign up

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