Spider参数
crawl使用
-a选项在命令中传递。例如：
scrapy crawl myspider -a category=electronics -a domain=system
Spider程序可以将参数作为属性访问：
class MySpider(scrapy.Spider): name = 'myspider' def __init__(self, category='', **kwargs): self.start_urls = [f'http://www.example.com/{category}'] # py36 super().__init__(**kwargs) # python3 def parse(self, response) self.log(self.domain) # system摘自Scrapy文档：http ://doc.scrapy.org/en/latest/topics/spiders.html#spider-arguments
# previouslysuper(MySpider, self).__init__(**kwargs) # python2
