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

# previously
super(MySpider, self).__init__(**kwargs)  # python2