Xpath只给了我第一个项目，而我想要所有的项目(使用Scrapy)

# 选择所有的div标签
response.xpath('//div')

# 选择所有的li标签下的a标签
response.xpath('//li//a')

# 选择前三个div标签
response.xpath('(//div)[position() <= 3]')

# 选择所有class为example的div标签
response.xpath('//div[contains(@class, "example")]')

<div class="book">
    <h2>Title 1</h2>
</div>
<div class="book">
    <h2>Title 2</h2>
</div>
<div class="book">
    <h2>Title 3</h2>
</div>

import scrapy

class BookSpider(scrapy.Spider):
    name = 'book_spider'
    start_urls = ['http://example.com/books']

    def parse(self, response):
        for book in response.xpath('//div[@class="book"]'):
            title = book.xpath('.//h2/text()').get()
            yield {'title': title}