这是我写的某网站抓取标题的爬虫,请问如何控制抓取次数?

import json
import logging

import scrapy

from news.items import NewsItem


class AbcSpider(scrapy.Spider):
    name = 'abc'
    allowed_domains = ['gelonghui.com']
    start_urls = ['https://www.gelonghui.com/api/channels/web_home_page/articles/v8?']




    def parse(self, response):
        item = NewsItem()
        dicts = json.loads(response.text)
        for dict in dicts['result']:
            item['title'] = dict['data']['title']
            logging.critical(item)
            yield item

        next_timestamp = dicts['result'][14]['data']['timestamp'] - 1
        url_ajax = 'https://www.gelonghui.com/api/channels/web_home_page/articles/v8?'
        data = {
            'timestamp': str(next_timestamp),
            'loaded': '15'
        }

        yield scrapy.FormRequest(url=url_ajax,
                                 method='get',
                                 formdata=data,
                                 dont_filter=True,
                                 callback=self.parse
                                 )

```python

```

可以用meta累计请求次数，在后续的请求中获取请求次数。

def parse(self, response):
meta = {'crawlCnt': 0}
if response.meta:
meta = response.meta
meta['crawlCnt'] += 1
......
yield scrapy.FormRequest(url=url_ajax,
method='get',
formdata=data,
dont_filter=True,
meta=meta,
callback=self.parse
)

最简单的办法，可能不好用，就是把你爬取的标题存入列表数组，每次判断这个列表的长度，达到你想要你数量结束函数