1. in acconda prompt, run shell
scrapy shell some_url
2. test response
print(response.text)
3. css selector
response.css('li.active')
4. get html by css selector
response.css('li.active').extract()
5. get text, it returns a array
response.css('li.active::text').extract()
6. get single text, it returns a string
response.css('li.active::text')[0].extract()
//or
response.css('li.active::text').extract_first()
