小编典典

Scrapy-从表中提取项目

scrapy

试图绕过Scrapy,但遇到了一些死胡同。

我在页面上有2个表,并希望从每个表中提取数据,然后移至下一页。

表格看起来像这样(第一个称为Y1,第二个称为Y2),并且结构相同。

<div id="Y1" style="margin-bottom: 0px; margin-top: 15px;">
                                <h2>First information</h2><hr style="margin-top: 5px; margin-bottom: 10px;">                    

                <table class="table table-striped table-hover table-curved">
                    <thead>
                        <tr>
                            <th class="tCol1" style="padding: 10px;">First Col Head</th>
                            <th class="tCol2" style="padding: 10px;">Second Col Head</th>
                            <th class="tCol3" style="padding: 10px;">Third Col Head</th>
                        </tr>
                    </thead>
                    <tbody>

                        <tr>
                            <td>Info 1</td>
                            <td>Monday 5 September, 2016</td>
                            <td>Friday 21 October, 2016</td>
                        </tr>
                        <tr class="vevent">
                            <td class="summary"><b>Info 2</b></td>
                            <td class="dtstart" timestamp="1477094400"><b></b></td>
                            <td class="dtend" timestamp="1477785600">
                            <b>Sunday 30 October, 2016</b></td>
                        </tr>
                        <tr>
                            <td>Info 3</td>
                            <td>Monday 31 October, 2016</td>
                            <td>Tuesday 20 December, 2016</td>
                        </tr>


                    <tr class="vevent">
                        <td class="summary"><b>Info 4</b></td>                      
                        <td class="dtstart" timestamp="1482278400"><b>Wednesday 21 December, 2016</b></td>
                        <td class="dtend" timestamp="1483315200">
                        <b>Monday 2 January, 2017</b></td>
                    </tr>



                </tbody>
            </table>

如你所见,结构有点不一致,但是只要我可以获取每个td并将其输出到csv,那么我就会很高兴。

我尝试使用xPath,但这只会让我更加困惑。

我最后的尝试:

import scrapy

class myScraperSpider(scrapy.Spider):
name = "myScraper"

allowed_domains = ["mysite.co.uk"]
start_urls =    (
                'https://mysite.co.uk/page1/',
                )

def parse_products(self, response):
    products = response.xpath('//*[@id="Y1"]/table')
    # ignore the table header row
    for product in products[1:]  
       item = Schooldates1Item()
       item['hol'] = product.xpath('//*[@id="Y1"]/table/tbody/tr[1]/td[1]').extract()[0]
       item['first'] = product.xpath('//*[@id="Y1"]/table/tbody/tr[1]/td[2]').extract()[0]
       item['last'] = product.xpath('//*[@id="Y1"]/table/tbody/tr[1]/td[3]').extract()[0]
       yield item

此处没有错误,但仅会激发出许多有关爬网的信息,但没有实际结果。

更新:

  import scrapy

       class SchoolSpider(scrapy.Spider):
name = "school"

allowed_domains = ["termdates.co.uk"]
start_urls =    (
                'https://termdates.co.uk/school-holidays-16-19-abingdon/',
                )

  def parse_products(self, response):
  products = sel.xpath('//*[@id="Year1"]/table//tr')
 for p in products[1:]:
  item = dict()
  item['hol'] = p.xpath('td[1]/text()').extract_first()
  item['first'] = p.xpath('td[1]/text()').extract_first()
  item['last'] = p.xpath('td[1]/text()').extract_first()
  yield item

这给了我:IndentationError:意外的缩进

如果我运行下面的修订脚本(感谢@Granitosaurus)以输出到CSV(-o schoolDates.csv),则会得到一个空文件:

import scrapy

class SchoolSpider(scrapy.Spider):
name = "school"
allowed_domains = ["termdates.co.uk"]
start_urls = ('https://termdates.co.uk/school-holidays-16-19-abingdon/',)

def parse_products(self, response):
    products = sel.xpath('//*[@id="Year1"]/table//tr')
    for p in products[1:]:
        item = dict()
        item['hol'] = p.xpath('td[1]/text()').extract_first()
        item['first'] = p.xpath('td[1]/text()').extract_first()
        item['last'] = p.xpath('td[1]/text()').extract_first()
        yield item

这是日志:

2017-03-23 12:04:08 [scrapy.core.engine] INFO: Spider opened 2017-03-23 12:04:08 [scrapy.extensions.logstats] INFO: Crawled 0 pages (at 0 pages/min), scraped 0 items (at 0 items/min) 2017-03-23 12:04:08 [scrapy.extensions.telnet] DEBUG: Telnet console listening on ... 2017-03-23 12:04:08 [scrapy.core.engine] DEBUG: Crawled (200) https://termdates.co.uk/robots.txt> (referer: None) 2017-03-23 12:04:08 [scrapy.core.engine] DEBUG: Crawled (200) https://termdates.co.uk/school-holidays-16-19-abingdon/> (referer: None) 2017-03-23 12:04:08 [scrapy.core.scraper] ERROR: Spider error processing https://termdates.co.uk/school-holidays-16-19-abingdon/> (referer: None) Traceback (most recent call last): File "c:\python27\lib\site-packages\twisted\internet\defer.py", line 653, in _ runCallbacks current.result = callback(current.result, *args, **kw) File "c:\python27\lib\site-packages\scrapy-1.3.3-py2.7.egg\scrapy\spiders__init__.py", line 76, in parse raise NotImplementedError NotImplementedError 2017-03-23 12:04:08 [scrapy.core.engine] INFO: Closing spider (finished) 2017-03-23 12:04:08 [scrapy.statscollectors] INFO: Dumping Scrapy stats: {'downloader/request_bytes': 467, 'downloader/request_count': 2, 'downloader/request_method_count/GET': 2, 'downloader/response_bytes': 11311, 'downloader/response_count': 2, 'downloader/response_status_count/200': 2, 'finish_reason': 'finished', 'finish_time': datetime.datetime(2017, 3, 23, 12, 4, 8, 845000), 'log_count/DEBUG': 3, 'log_count/ERROR': 1, 'log_count/INFO': 7, 'response_received_count': 2, 'scheduler/dequeued': 1, 'scheduler/dequeued/memory': 1, 'scheduler/enqueued': 1, 'scheduler/enqueued/memory': 1, 'spider_exceptions/NotImplementedError': 1, 'start_time': datetime.datetime(2017, 3, 23, 12, 4, 8, 356000)} 2017-03-23 12:04:08 [scrapy.core.engine] INFO: Spider closed (finished)

更新2:(跳过行)这会将结果推送到csv文件,但跳过每隔一行。

命令行管理程序显示 {‘hol’:None,’last’:u’\ r \ n \ t \ t \ t \ t \ t \ t \ t \ t’,’first’:None}

import scrapy

class SchoolSpider(scrapy.Spider):
name = "school"
allowed_domains = ["termdates.co.uk"]
start_urls = ('https://termdates.co.uk/school-holidays-16-19-abingdon/',)

def parse(self, response):
    products = response.xpath('//*[@id="Year1"]/table//tr')
    for p in products[1:]:
        item = dict()
        item['hol'] = p.xpath('td[1]/text()').extract_first()
        item['first'] = p.xpath('td[2]/text()').extract_first()
        item['last'] = p.xpath('td[3]/text()').extract_first()
        yield item

解决方案:这将爬网start_urls中的所有页面并处理不一致的表布局

# -*- coding: utf-8 -*-
import scrapy
from SchoolDates_1.items import Schooldates1Item

class SchoolSpider(scrapy.Spider):
name = "school"
allowed_domains = ["termdates.co.uk"]
start_urls = ('https://termdates.co.uk/school-holidays-16-19-abingdon/',
              'https://termdates.co.uk/school-holidays-3-dimensions',)

def parse(self, response):
    products = response.xpath('//*[@id="Year1"]/table//tr')
    # ignore the table header row
    for product in products[1:]:
        item = Schooldates1Item()
        item['hol'] = product.xpath('td[1]//text()').extract_first()
        item['first'] = product.xpath('td[2]//text()').extract_first()
        item['last'] = ''.join(product.xpath('td[3]//text()').extract()).strip()
        item['url'] = response.url
        yield item

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2020-04-09

共1个答案

小编典典

需要稍微更正你的代码。由于你已经选择了表中的所有元素,因此无需再次指向表。因此,你可以将xpath缩短为此类td[1]//text()

def parse_products(self, response):
    products = response.xpath('//*[@id="Year1"]/table//tr')
    # ignore the table header row
    for product in products[1:]  
       item = Schooldates1Item()
       item['hol'] = product.xpath('td[1]//text()').extract_first()
       item['first'] = product.xpath('td[2]//text()').extract_first()
       item['last'] = product.xpath('td[3]//text()').extract_first()
       yield item
2020-04-09