Scrapy + selenium requests twice for each url

问题

import scrapy 
from selenium import webdriver

class ProductSpider(scrapy.Spider):
    name = "product_spider"
    allowed_domains = ['ebay.com']
    start_urls = ['http://www.ebay.com/sch/i.html?_odkw=books&_osacat=0&_trksid=p2045573.m570.l1313.TR0.TRC0.Xpython&_nkw=python&_sacat=0&_from=R40']

    def __init__(self):
        self.driver = webdriver.Firefox()

    def parse(self, response):
        self.driver.get(response.url)

        while True:
            next = self.driver.find_element_by_xpath('//td[@class="pagn-next"]/a')

            try:
                next.click()

                # get the data and write it to scrapy items
            except:
                break

        self.driver.close()

selenium with scrapy for dynamic page

This solution works good, but it requests twice for the same url one by scrapy scheduler and another by the selenium web driver.

It'll take twice the time to finish the job, compared to scrapy request without selenium. How to avoid this?

回答1:

Here is a trick that can be useful to solve this problem.

create a web service for the selenium run it, locally

from flask import Flask, request, make_response
from flask_restful import Resource, Api
from selenium import webdriver
from selenium.webdriver.chrome.options import Options

app = Flask(__name__)
api = Api(app)

class Selenium(Resource):
    _driver = None

    @staticmethod
    def getDriver():
        if not Selenium._driver:
            chrome_options = Options()
            chrome_options.add_argument("--headless")

            Selenium._driver = webdriver.Chrome(chrome_options=chrome_options)
        return Selenium._driver

    @property
    def driver(self):
        return Selenium.getDriver()

    def get(self):
        url = str(request.args['url'])

        self.driver.get(url)

        return make_response(self.driver.page_source)

api.add_resource(Selenium, '/')

if __name__ == '__main__':
    app.run(debug=True)

now http://127.0.0.1:5000/?url=https://stackoverflow.com/users/5939254/yash-pokar will return you the compiled web page using selenium Chrome/Firefox driver.

now how our spider will look like,

import scrapy
import urllib


class ProductSpider(scrapy.Spider):
    name = 'products'
    allowed_domains = ['ebay.com']
    urls = [
        'http://www.ebay.com/sch/i.html?_odkw=books&_osacat=0&_trksid=p2045573.m570.l1313.TR0.TRC0.Xpython&_nkw=python&_sacat=0&_from=R40',
    ]

    def start_requests(self):
        for url in self.urls:
            url = 'http://127.0.0.1:5000/?url={}'.format(urllib.quote(url))
            yield scrapy.Request(url)

    def parse(self, response):
        yield {
            'field': response.xpath('//td[@class="pagn-next"]/a'),
        }

来源：https://stackoverflow.com/questions/50714354/scrapy-selenium-requests-twice-for-each-url

标签

python

selenium

web-scraping

scrapy