Uso de Proxies en Python con Playwright

Uso de Proxies en Python con Playwright

Playwright y Proxies

Playwright es un framework de automatización de navegadores de Microsoft, compatible con Chromium, Firefox y WebKit. La versión de Python de Playwright tiene soporte de proxy incorporado a nivel de navegador y para contextos individuales.

Instalación

pip install playwright
playwright install  # descarga navegadores

Configuración Básica de Proxy

Proxy HTTP

from playwright.sync_api import sync_playwright

with sync_playwright() as p:
    browser = p.chromium.launch(
        proxy={
            "server": "http://proxy_ip:port"
        }
    )
    page = browser.new_page()
    page.goto("https://httpbin.org/ip")
    print(page.content())
    browser.close()

Con Autenticación

from playwright.sync_api import sync_playwright

with sync_playwright() as p:
    browser = p.chromium.launch(
        proxy={
            "server": "http://proxy_ip:port",
            "username": "user",
            "password": "pass"
        }
    )
    page = browser.new_page()
    page.goto("https://httpbin.org/ip")
    print(page.content())
    browser.close()

Proxy SOCKS5

browser = p.chromium.launch(
    proxy={"server": "socks5://proxy_ip:port"}
)

Modo Asíncrono

import asyncio
from playwright.async_api import async_playwright

async def main():
    async with async_playwright() as p:
        browser = await p.chromium.launch(
            proxy={
                "server": "http://proxy_ip:port",
                "username": "user",
                "password": "pass"
            }
        )
        page = await browser.new_page()
        await page.goto("https://httpbin.org/ip")
        content = await page.content()
        print(content)
        await browser.close()

asyncio.run(main())

Proxies a Nivel de Contexto

Playwright te permite configurar diferentes proxies para distintos contextos (perfiles) dentro de un mismo navegador:

from playwright.sync_api import sync_playwright

with sync_playwright() as p:
    browser = p.chromium.launch()

    # Contexto 1 — proxy de EE. UU.
    context1 = browser.new_context(
        proxy={
            "server": "http://us_proxy:port",
            "username": "user",
            "password": "pass"
        }
    )

    # Contexto 2 — proxy de Alemania
    context2 = browser.new_context(
        proxy={
            "server": "http://de_proxy:port",
            "username": "user",
            "password": "pass"
        }
    )

    page1 = context1.new_page()
    page2 = context2.new_page()

    page1.goto("https://httpbin.org/ip")
    page2.goto("https://httpbin.org/ip")

    print("US:", page1.content())
    print("DE:", page2.content())

    browser.close()

Esta es una característica potente: un navegador, múltiples contextos con diferentes proxies y huellas digitales.

Omitiendo Proxies para Dominios Específicos

browser = p.chromium.launch(
    proxy={
        "server": "http://proxy_ip:port",
        "bypass": "localhost,*.local,example.com"
    }
)

Los dominios en la lista de bypass se acceden directamente, omitiendo el proxy.

Modos Headless y Headed

# Headless (sin GUI) — para scraping
browser = p.chromium.launch(headless=True, proxy={"server": "http://proxy:port"})

# Headed (con GUI) — para depuración
browser = p.chromium.launch(headless=False, proxy={"server": "http://proxy:port"})

Trabajando con Diferentes Navegadores

Playwright soporta tres motores:

# Chromium
browser = p.chromium.launch(proxy=proxy_config)

# Firefox
browser = p.firefox.launch(proxy=proxy_config)

# WebKit (Safari)
browser = p.webkit.launch(proxy=proxy_config)

Los tres soportan proxies de forma idéntica.

Modo Sigiloso y Evasión Anti-bot

Playwright es detectado por sistemas anti-bot. Para eludirlo:

playwright-stealth

pip install playwright-stealth

from playwright.sync_api import sync_playwright
from playwright_stealth import stealth_sync

with sync_playwright() as p:
    browser = p.chromium.launch(proxy={"server": "http://proxy:port"})
    page = browser.new_page()
    stealth_sync(page)  # aplica parches de sigilo
    page.goto("https://target-site.com")

Recomendaciones de Evasión

1. Usa proxies residenciales o móviles
2. Configura un User-Agent realista
3. Configura el tamaño del viewport
4. Añade retrasos entre acciones
5. Simula movimientos del ratón y desplazamiento

Capturas de Pantalla y PDFs vía Proxy

page.goto("https://example.com")
page.screenshot(path="screenshot.png", full_page=True)
page.pdf(path="page.pdf")

Interceptando Solicitudes

def handle_route(route):
    # Modificando solicitudes
    headers = route.request.headers
    headers["X-Custom-Header"] = "value"
    route.continue_(headers=headers)

page.route("**/*", handle_route)
page.goto("https://example.com")

Ejemplo Práctico: Scraping con Rotación

import asyncio
from playwright.async_api import async_playwright
import random

PROXIES = [
    {"server": "http://proxy1:port", "username": "u", "password": "p"},
    {"server": "http://proxy2:port", "username": "u", "password": "p"},
    {"server": "http://proxy3:port", "username": "u", "password": "p"},
]

async def scrape_page(playwright, url):
    proxy = random.choice(PROXIES)
    browser = await playwright.chromium.launch(proxy=proxy)
    page = await browser.new_page()
    try:
        await page.goto(url, timeout=30000)
        title = await page.title()
        return title
    except Exception as e:
        return f"Error: {e}"
    finally:
        await browser.close()

async def main():
    urls = [f"https://example.com/page/{i}" for i in range(10)]
    async with async_playwright() as p:
        tasks = [scrape_page(p, url) for url in urls]
        results = await asyncio.gather(*tasks)
        for url, result in zip(urls, results):
            print(f"{url}: {result}")

asyncio.run(main())

Conclusión

Playwright es una herramienta potente para trabajar con proxies en Python. El soporte de proxy a nivel de contexto permite ejecutar múltiples sesiones con diferentes IPs dentro de un mismo navegador. Combinado con parches de sigilo y proxies residenciales, Playwright es eficaz para el scraping de sitios web protegidos.