# 爬虫启动时触发
spider_opened = 'spider_opened'
# 爬虫关闭时触发
spider_closed = 'spider_closed'
# 爬虫异常时触发
spider_error = 'spider_error'
# 发起请求时触发
request_received = 'request_received'
# 获取到响应时触发
response_received = 'response_received'
# 生成item时触发
item_scraped = 'item_scraped'
