所以我正在制作几个scraper，现在我正试图制作一个脚本，用从数据库收集的URL运行相应的spider，但我找不到实现这一点的方法。
我的蜘蛛里有这个：
class ElCorteIngles(scrapy.Spider):
name = 'ElCorteIngles'
url = ''
DEBUG = False
def start_requests(self):
if self.url != '':
yield scrapy.Request(url=self.url, callback=self.parse)
def parse(self, response):
# Get product name
try:
self.p_name = response.xpath('//*[@id="product-info"]/h2[1]/a/text()').get()
except:
print(f'{CERROR} Problem while getting product name from website - {self.name}')
# Get product price
try:
self.price_no_cent = response.xpath('//*[@id="price-container"]/div/span[2]/text()').get()
self.cent = response.xpath('//*[@id="price-container"]/div/span[2]/span[1]/text()').get()
self.currency = response.xpath('//*[@id="price-container"]/div/span[2]/span[2]/text()').get()
if self.currency == None:
self.currency = response.xpath('//*[@id="price-container"]/div/span[2]/span[1]/text()').get()
self.cent = None
except:
print(f'{CERROR} Problem while getting product price from website - {self.name}')
# Join self.price_no_cent with self.cent
try:
if self.cent != None:
self.price = str(self.price_no_cent) + str(self.cent)
self.price = self.price.replace(',', '.')
else:
self.price = self.price_no_cent
except:
print(f'{ERROR} Problem while joining price with cents - {self.name}')
# Return data
if self.DEBUG == True:
print([self.p_name, self.price, self.currency])
data_collected = ShopScrapersItems()
data_collected['url'] = response.url
data_collected['p_name'] = self.p_name
data_collected['price'] = self.price
data_collected['currency'] = self.currency
yield data_collected
通常，当我从控制台运行spider时，我会：
scrapy crawl ElCorteIngles -a url='https://www.elcorteingles.pt/electrodomesticos/A26601428-depiladora-braun-senso-smart-5-5500/'
现在我需要一种方法来对外部脚本执行同样的操作，并获得输出yield data_collected
我目前在外部脚本中的内容是：
import scrapy
from scrapy.crawler import CrawlerProcess
import sqlalchemy as db
# Import internal libraries
from Ruby.Ruby.spiders import *
# Variables
engine = db.create_engine('mysql+pymysql://DATABASE_INFO')
class Worker(object):
def __init__(self):
self.crawler = CrawlerProcess({})
def scrape_new_links(self):
conn = engine.connect()
# Get all new links from DB and scrape them
query = 'SELECT * FROM Ruby.New_links'
result = conn.execute(query)
for x in result:
telegram_id = x[1]
email = x[2]
phone_number = x[3]
url = x[4]
spider = x[5]
# In this cade the spider will be ElCorteIngles and
# the url https://www.elcorteingles.pt/electrodomesticos/A26601428-depiladora-
# braun-senso-smart-5-5500/'
self.crawler.crawl(spider, url=url)
self.crawler.start()
Worker().scrape_new_links()
我也不知道在self.crawler.crawl()中执行url=url是否是向蜘蛛提供URL的正确方法，但请告诉我你的想法。来自yield的所有数据都由管道返回。我认为不需要额外的信息，但如果你需要任何信息，请告诉我！
Scrapy异步工作。。。忽略我的导入，但这是我为scraby创建的JSON api。您需要制作一个带有item_scraped信号的自定义runner。最初有一个klein端点，当spider完成时，它将返回一个JSON列表。我想这是你想要的，但没有克莱恩终点，所以我把它去掉了。我的蜘蛛是GshopSpider，我把它换成了你的蜘蛛名字。
通过利用延迟，我们能够在每次刮取项目时使用回调并发送信号。因此，使用此代码，我们将每个项目收集到一个带有信号的列表中，当spider完成时，我们有一个回调设置来返回_spider_output
# server.py
import json
from scrapy import signals
from scrapy.crawler import CrawlerRunner
from googleshop.spiders.gshop import GshopSpider
from scrapy.utils.project import get_project_settings
class MyCrawlerRunner(CrawlerRunner):
def crawl(self, crawler_or_spidercls, *args, **kwargs):
# keep all items scraped
self.items = []
crawler = self.create_crawler(crawler_or_spidercls)
crawler.signals.connect(self.item_scraped, signals.item_scraped)
dfd = self._crawl(crawler, *args, **kwargs)
dfd.addCallback(self.return_items)
return dfd
def item_scraped(self, item, response, spider):
self.items.append(item)
def return_items(self, result):
return self.items
def return_spider_output(output):
return json.dumps([dict(item) for item in output])
if __name__=="__main__"
settings = get_project_settings()
runner = MyCrawlerRunner(settings)
spider = ElCorteIngles()
deferred = runner.crawl(spider)
deferred.addCallback(return_spider_output)
return deferred
最简单的方法如下：
class ElCorteIngles(scrapy.Spider):
name = 'ElCorteIngles'
url = ''
DEBUG = False
def __init__(self):
super().__init__(self, **kwargs)
# Establish your db connection here. This can be any database connection.
# Reuse this connection object anywhere else
self.conn = conn = engine.connect()
def start_requests(self):
with self.conn.cursor() as cursor:
cursor.execute('''SELECT * FROM Ruby.New_links WHERE url NOT NULL OR url != %s''', ('',))
result = cursor.fetchall()
for url in result:
yield scrapy.Request(url=url, dont_filter=True, callback=self.parse)
def parse(self):
# Your Parse code here
完成此操作后，您可以使用类似的东西启动此爬网程序
from scrapy.crawler import CrawlerProcess
from scrapy.utils.project import get_project_settings
from project_name.spiders.filename import ElCorteIngles
process = CrawlerProcess(get_project_settings())
process.crawl(ElCorteIngles)
process.start()
希望这能有所帮助。
如果您使用大量URL，我还建议您使用队列。这将使多个spider进程能够并行处理这些URL。您可以在init方法中启动队列。