Question

我正在使用scrapy框架废弃网站，并且无法点击javascript链接以打开其他网页。

我可以将页面上的代码标识为：

<a class="Page" alt="Click to view job description" title="Click to view job description" href="javascript:sysSubmitForm('frmSR1');">Accountant&nbsp;</a>

任何人都可以建议我如何在scaroy中执行该javascript并通过我可以从该页面获取数据来获取另一页。

提前致谢

Answer 1

查看以下内容，了解如何使用硒进行scrapy。爬行将会变慢，因为您不仅可以下载html，还可以完全访问DOM。

注意：我已复制粘贴此代码段，因为之前提供的链接不再有效。

# Snippet imported from snippets.scrapy.org (which no longer works)

from scrapy.contrib.spiders import CrawlSpider, Rule
from scrapy.contrib.linkextractors.sgml import SgmlLinkExtractor
from scrapy.selector import HtmlXPathSelector
from scrapy.http import Request

from selenium import selenium

class SeleniumSpider(CrawlSpider):
    name = "SeleniumSpider"
    start_urls = ["http://www.domain.com"]

    rules = (
        Rule(SgmlLinkExtractor(allow=('\.html', )),
        callback='parse_page',follow=True),
    )

    def __init__(self):
        CrawlSpider.__init__(self)
        self.verificationErrors = []
        self.selenium = selenium("localhost", 4444, "*chrome", "http://www.domain.com")
        self.selenium.start()

    def __del__(self):
        self.selenium.stop()
        print self.verificationErrors
        CrawlSpider.__del__(self)

    def parse_page(self, response):
        item = Item()

        hxs = HtmlXPathSelector(response)
        #Do some XPath selection with Scrapy
        hxs.select('//div').extract()

        sel = self.selenium
        sel.open(response.url)

        #Wait for javscript to load in Selenium
        time.sleep(2.5)

        #Do some crawling of javascript created content with Selenium
        sel.get_text("//div")
        yield item

Answer 2

如果你想查看一个使用scrapy和selenium的相当庞大的功能代码库，请查看https://github.com/nicodjimenez/bus_catchers。这是一个更简单的例子。

# stripped down BoltBus script 
from selenium import webdriver
from selenium.common.exceptions import TimeoutException
from selenium.webdriver.support.ui import WebDriverWait 
from selenium.webdriver.support import expected_conditions as EC
from selenium.webdriver.common.keys import Keys
from scrapy.selector import HtmlXPathSelector
from scrapy.http import Response 
from scrapy.http import TextResponse 
import time

# set dates, origin, destination 
cityOrigin="Baltimore"
cityDeparture="New York"
day_array=[0]
browser = webdriver.Firefox()

# we are going the day of the days of the month from 15,16,...,25
# there is a discrepancy between the index of the calendar days and the day itself: for example day[10] may correspond to Feb 7th
for day in day_array:

    # Create a new instance of the Firefox driver
    browser.get("http://www.boltbus.com")

    # click on "region" tab
    elem_0=browser.find_element_by_id("ctl00_cphM_forwardRouteUC_lstRegion_textBox")
    elem_0.click()
    time.sleep(5) 

    # select Northeast
    elem_1=browser.find_element_by_partial_link_text("Northeast")
    elem_1.click()
    time.sleep(5)

    # click on origin city
    elem_2=browser.find_element_by_id("ctl00_cphM_forwardRouteUC_lstOrigin_textBox")
    elem_2.click()
    time.sleep(5)

    # select origin city
    elem_3=browser.find_element_by_partial_link_text(cityOrigin)
    elem_3.click()
    time.sleep(5)

    # click on destination city 
    elem_4=browser.find_element_by_id("ctl00_cphM_forwardRouteUC_lstDestination_textBox")
    elem_4.click()
    time.sleep(5)

    # select destination city 
    elem_5=browser.find_element_by_partial_link_text(cityDeparture)
    elem_5.click()
    time.sleep(5)

    # click on travel date
    travel_date_elem=browser.find_element_by_id("ctl00_cphM_forwardRouteUC_imageE")
    travel_date_elem.click()    

    # gets day rows of table
    date_rows=browser.find_elements_by_class_name("daysrow") 

    # select actual day (use variable day)
    # NOTE: you must make sure these day elements are "clickable"
    days=date_rows[0].find_elements_by_xpath("..//td")
    days[day].click()
    time.sleep(3) 

    # retrieve actual departure date from browser
    depart_date_elem=browser.find_element_by_id("ctl00_cphM_forwardRouteUC_txtDepartureDate")
    depart_date=str(depart_date_elem.get_attribute("value"))

    # PARSE TABLE

    # convert html to "nice format"
    text_html=browser.page_source.encode('utf-8')
    html_str=str(text_html)

    # this is a hack that initiates a "TextResponse" object (taken from the Scrapy module)
    resp_for_scrapy=TextResponse('none',200,{},html_str,[],None)

    # takes a "TextResponse" object and feeds it to a scrapy function which will convert the raw HTML to a XPath document tree
    hxs=HtmlXPathSelector(resp_for_scrapy)

    # the | sign means "or"
    table_rows=hxs.select('//tr[@class="fareviewrow"] | //tr[@class="fareviewaltrow"]')
    row_ct=len(table_rows)

    for x in xrange(row_ct):

        cur_node_elements=table_rows[x]
        travel_price=cur_node_elements.select('.//td[@class="faresColumn0"]/text()').re("\d{1,3}\.\d\d")

        # I use a mixture of xpath selectors to get me to the right location in the document, and regular expressions to get the exact data

        # actual digits of time 
        depart_time_num=cur_node_elements.select('.//td[@class="faresColumn1"]/text()').re("\d{1,2}\:\d\d")

        # AM or PM (time signature)
        depart_time_sig=cur_node_elements.select('.//td[@class="faresColumn1"]/text()').re("[AP][M]")

        # actual digits of time 
        arrive_time_num=cur_node_elements.select('.//td[@class="faresColumn2"]/text()').re("\d{1,2}\:\d\d")

        # AM or PM (time signature)
        arrive_time_sig=cur_node_elements.select('.//td[@class="faresColumn2"]/text()').re("[AP][M]")

        print "Depart date: " + depart_date
        print "Depart time: " + depart_time_num[0] + " " + depart_time_sig[0]   
        print "Arrive time: " + arrive_time_num[0] + " " + arrive_time_sig[0]
        print "Cost: " + "$" + travel_price[0] 
        print "\n"

Answer 3

据我所知，在urrlib2和urllib上实现的scrappy crawler显然不适用于js。对于使用js，您可以使用qt webkit或selenium。或者您可以在页面上找到所有ajax链接，并查看如何实现与服务器的数据交换并间接向服务器api发送响应。

执行Javascript使用python中的scrapy提交表单函数

3 个答案: