Scrapy，从第二组链接中抓取页面 [英] Scrapy, scrape pages from second set of links
问题描述
我今天一直在浏览 Scrapy 文档并试图获得一个工作版本 - https://docs.scrapy.org/en/latest/intro/tutorial.html#our-first-spider - 一个真实世界的例子.我的示例略有不同，因为它有 2 个下一页，即
I've been going through the Scrapy documentation today and trying to get a working version of - https://docs.scrapy.org/en/latest/intro/tutorial.html#our-first-spider - on a real world example. My example is slightly different in that it has 2 next pages, i.e.
start_url > 城市页面 > 单位页面
start_url > city page > unit page
这是我要从中抓取数据的单位页面.
It is the unit pages I want to grab data from.
我的代码:
import scrapy
class QuotesSpider(scrapy.Spider):
name = "quotes"
start_urls = [
'http://www.unitestudents.com/',
]
def parse(self, response):
for quote in response.css('div.property-body'):
yield {
'name': quote.xpath('//span/a/text()').extract(),
'type': quote.xpath('//div/h4/text()').extract(),
'price_amens': quote.xpath('//div/p/text()').extract(),
'distance_beds': quote.xpath('//li/p/text()').extract()
}
# Purpose is to crawl links of cities
next_page = response.css('a.listing-item__link::attr(href)').extract_first()
if next_page is not None:
next_page = response.urljoin(next_page)
yield scrapy.Request(next_page, callback=self.parse)
# Purpose is to crawl links of units
next_unit_page = response.css(response.css('a.text-highlight__inner::attr(href)').extract_first())
if next_unit_page is not None:
next_unit_page = response.urljoin(next_unit_page)
yield scrapy.Request(next_unit_page, callback=self.parse)
但是当我运行它时，我得到:
But when I run this I get:
INFO: Crawled 0 pages (at 0 pages/min), scraped 0 items (at 0 items/min)
所以我认为我的代码没有设置为检索上述流程中的链接，但我不确定如何最好地做到这一点?
So I am thinking my code is not set up to retrieve the links in the flow mentioned above, but am not sure how best to do that?
更新流程:
主页 > 城市页面 > 建筑页面 > 单位页面
Main page > City page > Building page > Unit page
它仍然是我想从中获取数据的单元页面.
It's still the unit page I want to get the data from.
更新代码:
import scrapy
class QuotesSpider(scrapy.Spider):
name = "quotes"
start_urls = [
'http://www.unitestudents.com/',
]
def parse(self, response):
for quote in response.css('div.site-wrapper'):
yield {
'area_name': quote.xpath('//div/ul/li/a/span/text()').extract(),
'type': quote.xpath('//div/div/div/h1/span/text()').extract(),
'period': quote.xpath('/html/body/div/div/section/div/form/h4/span/text()').extract(),
'duration_weekly': quote.xpath('//html/body/div/div/section/div/form/div/div/em/text()').extract(),
'guide_total': quote.xpath('//html/body/div/div/section/div/form/div/div/p/text()').extract(),
'amenities': quote.xpath('//div/div/div/ul/li/p/text()').extract(),
}
# Purpose is to crawl links of cities
next_page = response.xpath('//html/body/div/footer/div/div/div/ul/li/a[@class="listing-item__link"]/@href').extract()
if next_page is not None:
next_page = response.urljoin(next_page)
yield scrapy.Request(next_page, callback=self.parse)
# Purpose is to crawl links of units
next_unit_page = response.xpath('//li/div/h3/span/a/@href').extract()
if next_unit_page is not None:
next_unit_page = response.urljoin(next_unit_page)
yield scrapy.Request(next_unit_page, callback=self.parse)
# Purpose to crawl crawl pages on full unit info
last_unit_page = response.xpath('//div/div/div[@class="content__btn"]/a/@href').extract()
if last_unit_page is not None:
last_unit_page = response.urljoin(last_unit_page)
yield scrapy.Request(last_unit_page, callback=self.parse)
推荐答案
让我们从逻辑开始:
- 抓取主页 - 获取所有城市
- 抓取城市页面 - 获取所有单位网址
- 抓取单位页面 - 获取所有需要的数据
我已经举了一个例子，说明如何在下面的爬虫蜘蛛中实现这一点.我无法找到您在示例代码中提到的所有信息，但我希望代码足够清晰，让您了解它的作用以及如何添加您需要的信息.
I've made an example of how you could implement this in a scrapy spider below. I was not able to find all the info you mention in your example code, but I hope the code is clear enough for you to understand what it does and how to add the info you need.
import scrapy
class QuotesSpider(scrapy.Spider):
name = "quotes"
start_urls = [
'http://www.unitestudents.com/',
]
# Step 1
def parse(self, response):
for city in response.xpath('//select[@id="frm_homeSelect_city"]/option[not(contains(text(),"Select your city"))]/text()').extract(): # Select all cities listed in the select (exclude the "Select your city" option)
yield scrapy.Request(response.urljoin("/"+city), callback=self.parse_citypage)
# Step 2
def parse_citypage(self, response):
for url in response.xpath('//div[@class="property-header"]/h3/span/a/@href').extract(): #Select for each property the url
yield scrapy.Request(response.urljoin(url), callback=self.parse_unitpage)
# I could not find any pagination. Otherwise it would go here.
# Step 3
def parse_unitpage(self, response):
unitTypes = response.xpath('//div[@class="room-type-block"]/h5/text()').extract() + response.xpath('//h4[@class="content__header"]/text()').extract()
for unitType in unitTypes: # There can be multiple unit types so we yield an item for each unit type we can find.
yield {
'name': response.xpath('//h1/span/text()').extract_first(),
'type': unitType,
# 'price': response.xpath('XPATH GOES HERE'), # Could not find a price on the page
# 'distance_beds': response.xpath('XPATH GOES HERE') # Could not find such info
}
我认为代码非常干净和简单.评论应该阐明我为什么选择使用 for 循环.如果有什么不清楚的，请告诉我，我会尽力解释.
I think the code is pretty clean and simple. Comments should clarify why I chose to use the for loops. If something is not clear, let me know and I'll try to explain it.
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