scrapy-pyppeteer 0.0.15

Pyppeteer integration for Scrapy

Pyppeteer integration for Scrapy

This project provides a Scrapy Download Handler which performs requests using Pyppeteer. It can be used to handle pages that require JavaScript. This package does not interfere with regular Scrapy workflows such as request scheduling or item processing.

Motivation

After the release of version 2.0, which includes partial coroutine syntax support and experimental asyncio support, Scrapy allows to integrate asyncio-based projects such as Pyppeteer.

Requirements

• Python 3.6+
• Scrapy 2.0+
• Pyppeteer 0.0.23+

Installation

$ pip install scrapy-pyppeteer

Configuration

Replace the default http and https Download Handlers through DOWNLOAD_HANDLERS:

DOWNLOAD_HANDLERS = {
    "http": "scrapy_pyppeteer.handler.ScrapyPyppeteerDownloadHandler",
    "https": "scrapy_pyppeteer.handler.ScrapyPyppeteerDownloadHandler",
}

Note that the ScrapyPyppeteerDownloadHandler class inherits from the default http/https handler, and it will only use Pyppeteer for requests that are explicitly marked (see the "Basic usage" section for details).

Also, be sure to install the asyncio-based Twisted reactor:

TWISTED_REACTOR = "twisted.internet.asyncioreactor.AsyncioSelectorReactor"

scrapy-pyppeteer accepts the following settings:

• PYPPETEER_LAUNCH_OPTIONS (type dict, default {})

  A dictionary with options to be passed when launching the Browser. See the docs for pyppeteer.launcher.launch

• PYPPETEER_NAVIGATION_TIMEOUT (type Optional[int], default None)

  Default timeout (in milliseconds) to be used when requesting pages by Pyppeteer. If None or unset, the default value will be used (30000 ms at the time of writing this). See the docs for pyppeteer.page.Page.setDefaultNavigationTimeout

• PYPPETEER_PAGE_COROUTINE_TIMEOUT (type Optional[Union[int, float]], default None)

  Default timeout (in milliseconds) to be passed when using page coroutines, such as waitForSelector or waitForXPath. If None or unset, the default value will be used (30000 ms at the time of writing this).

Basic usage

Set the pyppeteer Request.meta key to download a request using Pyppeteer:

import scrapy

class AwesomeSpider(scrapy.Spider):
    name = "awesome"

    def start_requests(self):
        # GET request
        yield scrapy.Request("https://httpbin.org/get", meta={"pyppeteer": True})
        # POST request
        yield scrapy.FormRequest(
            url="https://httpbin.org/post",
            formdata={"foo": "bar"},
            meta={"pyppeteer": True},
        )

    def parse(self, response):
        # 'response' contains the page as seen by the browser
        yield {"url": response.url}

Page coroutines

A sorted iterable (list, tuple or dict, for instance) could be passed in the pyppeteer_page_coroutines Request.meta key to request coroutines to be awaited on the Page before returning the final Response to the callback.

This is useful when you need to perform certain actions on a page, like scrolling down or clicking links, and you want everything to count as a single Scrapy Response, containing the final result.

Supported actions

• scrapy_pyppeteer.page.PageCoroutine(method: str, *args, **kwargs):

  Represents a coroutine to be awaited on a pyppeteer.page.Page object, such as "click", "screenshot", "evaluate", etc. method should be the name of the coroutine, *args and **kwargs are passed to the function call.

  The coroutine result will be stored in the PageCoroutine.result attribute

  For instance,

  PageCoroutine("screenshot", options={"path": "quotes.png", "fullPage": True})
  

  produces the same effect as:

  # 'page' is a pyppeteer.page.Page object
  await page.screenshot(options={"path": "quotes.png", "fullPage": True})
  

• scrapy_pyppeteer.page.NavigationPageCoroutine(method: str, *args, **kwargs):

  Subclass of PageCoroutine. It waits for a navigation event: use this when you know a coroutine will trigger a navigation event, for instance when clicking on a link. This forces a Page.waitForNavigation() call wrapped in asyncio.gather, as recommended in the Pyppeteer docs.

  For instance,

  NavigationPageCoroutine("click", selector="a")
  

  produces the same effect as:

  # 'page' is a pyppeteer.page.Page object
  await asyncio.gather(
      page.waitForNavigation(),
      page.click(selector="a"),
  )
  

Receiving the Page object in the callback

Specifying pyppeteer.page.Page as the type for a callback argument will result in the corresponding Page object being injected in the callback. In order to able to await coroutines on the provided Page object, the callback needs to be defined as a coroutine function (async def).

import scrapy
import pyppeteer

class AwesomeSpiderWithPage(scrapy.Spider):
    name = "page"

    def start_requests(self):
        yield scrapy.Request("https://example.org", meta={"pyppeteer": True})

    async def parse(self, response, page: pyppeteer.page.Page):
        title = await page.title()  # "Example Domain"
        yield {"title": title}
        await page.close()

Notes:

• In order to avoid memory issues, it is recommended to manually close the page by awaiting the Page.close coroutine.
• Any network operations resulting from awaiting a coroutine on a Page object (goto, goBack, etc) will be executed directly by Pyppeteer, bypassing the Scrapy request workflow (Scheduler, Middlewares, etc).

Examples

Click on a link, save the resulting page as PDF

import scrapy
from scrapy_pyppeteer.page import PageCoroutine, NavigationPageCoroutine

class ClickAndSavePdfSpider(scrapy.Spider):
    name = "pdf"

    def start_requests(self):
        yield scrapy.Request(
            url="https://example.org",
            meta=dict(
                pyppeteer=True,
                pyppeteer_page_coroutines={
                    "click": NavigationPageCoroutine("click", selector="a"),
                    "pdf": PageCoroutine("pdf", options={"path": "/tmp/file.pdf"}),
                },
            ),
        )

    def parse(self, response):
        pdf_bytes = response.meta["pyppeteer_page_coroutines"]["pdf"].result
        with open("iana.pdf", "wb") as fp:
            fp.write(pdf_bytes)
        yield {"url": response.url}  # response.url is "https://www.iana.org/domains/reserved"

Scroll down on an infinite scroll page, take a screenshot of the full page

import scrapy
import pyppeteer
from scrapy_pyppeteer.page import PageCoroutine

class ScrollSpider(scrapy.Spider):
    name = "scroll"

    def start_requests(self):
        yield scrapy.Request(
            url="http://quotes.toscrape.com/scroll",
            meta=dict(
                pyppeteer=True,
                pyppeteer_page_coroutines=[
                    PageCoroutine("waitForSelector", "div.quote"),
                    PageCoroutine("evaluate", "window.scrollBy(0, document.body.scrollHeight)"),
                    PageCoroutine("waitForSelector", "div.quote:nth-child(11)"),  # 10 per page
                    PageCoroutine("screenshot", options={"path": "quotes.png", "fullPage": True}),
                ],
            ),
        )

    def parse(self, response):
        return {"quote_count": len(response.css("div.quote"))}

Acknowledgements

This project was inspired by:

• https://github.com/scrapy/scrapy/pull/1455
• https://github.com/michalmo/scrapy-browser
• https://github.com/lopuhin/scrapy-pyppeteer
• https://github.com/clemfromspace/scrapy-puppeteer