xpath ,css

https://docs.scrapy.org/en/latest/intro/tutorial.html

xpath @选择属性  .当前目录下选择 //任意路径选择

/bookstore/book[position()<3]，选取最前面的两个属于 bookstore 元素的子元素的 book 元素

css span.text::text

response.css("span.text").text().get() ///  AttributeError: 'SelectorList' object has no attribute 'text'

quote.css("span.text::text").get() 选择span下面text的text（）标签内容

scrapy crawl quotes -o quotes.json

That will generate an quotes.json file containing all scraped items, serialized in JSON.

For historic reasons, Scrapy appends to a given file instead of overwriting its contents. If you run this command twice without removing the file before the second time, you’ll end up with a broken JSON file.