Scrapy会先通过getattr判断我们是否自定义了from_crawler,有则调它来完 成实例化,早于__init__方法执行 自己要的参数要去settings.py文件配置 """ HOST = crawler.settings.get('HOST') PORT = crawler.settings.get('PORT') USER = crawler.settings.get('USER') PWD = crawler.settings.get('PWD') DB...
3. 接着,我们编写 run_spider.py 文件,并在其中注册我们想要启动的 Spider(使用 spider_name 变量)以下是代码示例: fromscrapy.crawlerimportCrawlerProcessfromscrapy.utils.projectimportget_project_settings defrun_spider():process = CrawlerProces...
from ScrapyDemo.itemsimportDouLuoDaLuItemclassCustomDoLuoDaLuPipeline(object):def__init__(self,dbpool):self.dbpool=dbpool @classmethod deffrom_crawler(cls,crawler):# 读取settings中的配置 params=dict(host=crawler.settings['MYSQL_HOST'],db=crawler.settings['MYSQL_DBNAME'],user=crawler.settings['MYS...
crawler属性在初始化class后,由类方法from_crawler设置, 并且链接了本spider实例对应的Crawl对象。Crawler包...
from scrapy.crawler import CrawlerProcess process = CrawlerProcess() process.crawl(MySpider) process.start() 在这个示例中,我们首先定义了一个名为MySpider的Scrapy爬虫,然后在custom_settings中配置了Crawlera的代理中间件和API密钥,以及代理信息。在parse方法中,我们使用scrapy.Request发送请求,并通过meta参数指定了...
from_crawler:一个类方法,这个方法是依赖注入的方式实现的。通过crawler,我们能拿到全局配置的每个信息,从而获取数据库的 配置信息,拿到之后返回类对象即可 open_spider:当Spider开启时,这个方法被调用,主要进行一些初始化的操作 close_spider:当Spider被关闭时,这个方法被调用,将数据库连接关闭 ...
from_crawler是在爬虫被初始化时执行的入口方法 spider = super(CcidcomSpider, cls).from_crawler(crawler, *args, **kwargs)是调用父类的方法, 获取到实例化的爬虫 crawler.signals.connect(spider.item_scraped, signal=signals.item_scraped)是将爬虫的spider.item_scraped方法注入到signals.item_scraped信号的位...
def from_crawler(cls, crawler): """ Pipelines的准备工作,通过crawler可以拿到全局配置的每个配置信息 :param crawler: :return: 类实例 """ # 使用类方法,返回带有MONGO_URI和MONGO_DB值的类实例 return cls( mongo_uri=crawler.settings.get('MONGO_URI'), # MONGO_URI的值从settings.py获取 ...
from scrapy import signalsfrom scrapy.exceptions import NotConfiguredclass SpiderOpenCloseLogging(object):def __init__(self):self.items_scraped = 0self.items_dropped = 0@classmethoddef from_crawler(cls, crawler):# 读取settings配置信息,检查是否启动扩展,没有启用则抛出异常,扩展被禁用if not crawler....
from scrapy import signals from scrapy.exceptions import NotConfigured class SpiderOpenCloseLogging(object): def __init__(self): self.items_scraped = 0 self.items_dropped = 0 @classmethod def from_crawler(cls, crawler): # 读取settings配置信息,检查是否启动扩展,没有启用则抛出异常,扩展被禁用 ...