link = LinkExtractor(
# Items只能是一個正則表達式,會提取當前頁面中滿足該"正則表達式"的url	
　 allow=r'Items/'
)

import scrapy
# 導入相關的包
from scrapy.linkextractors import LinkExtractor
from scrapy.spiders import CrawlSpider, Rule

class TextSpider(CrawlSpider):
 name = 'text'
 allowed_domains = ['www.xxx.com']
 start_urls = ['http://www.xxx.com/']

# 鏈接提取器,從接受到的response對象中,根據item正則表達式提取頁面中的鏈接
	link = LinkExtractor(allow=r'Items/')
	link2 = LinkExtractor(allow=r'Items/')
# 規則解析器,根據callback將鏈接提取器提取到的鏈接進行數據解析
# follow為true,則表示將鏈接提取器繼續作用到鏈接提取器所提取到的鏈接頁面中
# 故:在我們提取多頁數據時,若第一頁對應的網頁中包含了第2,3,4,5頁的鏈接,
# 當跳轉到第5頁時,第5頁又包含了第6,7,8,9頁的鏈接,
# 令follow=True,就可以持續作用,從而提取到所有頁面的鏈接
 rules = (Rule(link, callback='parse_item', follow=True),
 		Rule(link2,callback='parse_content',follow=False))
 # 鏈接提取器link使用parse_item解析數據
	def parse_item(self, response):
 item = {}
 
 yield item
 # 鏈接提取器link2使用parse_content解析數據
	def parse_content(self, response):
		item = {}
		
		yield item

scrapy genspider crawl -t spiderName www.xxx.com 

import scrapy
from scrapy.linkextractors import LinkExtractor

from scrapy.spiders import CrawlSpider, Rule
from gushiPro.items import GushiproItem,ContentItem

class GushiSpider(CrawlSpider):
 name = 'gushi'
 #allowed_domains = ['www.xxx.com']
 start_urls = ['https://www.gushiwen.org/']

 # 鏈接提取器:只能使用正則表達式，提取當前頁面的滿足allow條件的鏈接
 link = LinkExtractor(allow=r'/default_\d+\.aspx')

 # 鏈接提取器，提取所有標題對應的詳情頁url
 content_link = LinkExtractor(allow=r'cn/shiwenv_\w+\.aspx')
 rules = (
 # 規則解析器，需要解析所有的頁面，所有follow=True
 Rule(link, callback='parse_item', follow=True),

 # 不需要寫follow，因為我們只需要解析詳情頁中的數據，而不是詳情頁中的url
 Rule(content_link, callback='content_item'),
 )

 # 解析當前頁面的標題
 def parse_item(self, response):
 p_list = response.xpath('//div[@class="sons"]/div[1]/p[1]')

 for p in p_list:
 title = p.xpath('./a//text()').extract_first()
 item = GushiproItem()
 item['title'] = title
 yield item
 
 # 解析詳情頁面的標題和內容
 def content_item(self,response):
 # //div[@id="sonsyuanwen"]/div[@class="cont"]/div[@class="contson"]
 # 解析詳情頁面的內容
 content = response.xpath('//div[@id="sonsyuanwen"]/div[@class="cont"]/div[@class="contson"]//text()').extract()
 content = "".join(content)
 # # 解析詳情頁面的標題
 title = response.xpath('//div[@id="sonsyuanwen"]/div[@class="cont"]/h1/text()').extract_first()
 # print("title:"+title+"\ncontent:"+content)
 item = ContentItem()
 item["content"] = content
 item["title"] = title
 # 將itme對象傳給管道
 yield item

import scrapy

# 不同的item類是獨立的，他們可以創建不同的item對象
class GushiproItem(scrapy.Item):
 # define the fields for your item here like:
 # name = scrapy.Field()
 title = scrapy.Field()

class ContentItem(scrapy.Item):
 title = scrapy.Field()
 content = scrapy.Field()

from itemadapter import ItemAdapter

class GushiproPipeline:
 def __init__(self):
 self.fp = None

 def open_spider(self,spider):
 self.fp = open("gushi.txt",'w',encoding='utf-8')
 print("開始爬蟲")

 def process_item(self, item, spider):
 # 從詳情頁獲取標題和內容，所以需要判斷爬蟲文件中傳來的item是什么類的item
 # item.__class__.__name__判斷屬于什么類型的item
 if item.__class__.__name__ == "ContentItem":
 content = "《"+item['title']+"》",item['content']
 content = "".join(content) 
 print(content)
 self.fp.write(content)
 return item

 def close_spider(self,spider):
 self.fp.close()
 print("結束爬蟲")