scrapy爬取图片出现错误ValueError: Missing scheme in request url: //static.699pic.com/

[敲出亿行bug]

spider的代码


from scrapy import Request
from scrapy.spiders import Spider
from shetu_spider.items import ShetuSpiderItem

class image_download(Spider):
name = 'image'

def start_requests(self):
url = 'http://699pic.com/photo/'
yield Request(url)

def parse(self, response):#解析函数-图片列表页
urls = response.xpath("//div[@class='pl-list']/a[1]/@href").extract()
for i in range(len(urls)):
yield Request(('http:'+urls[i]),callback=self.parse_image)

def parse_image(self,response):
item = ShetuSpiderItem()

#获取所有图片url地址
url = response.xpath("//li[@class='list']/a/img/@src").extract()
if url:
title = response.xpath("//li[@class='list']/a/img/@title").extract()
item['title'] = title
item['image_urls']=url
yield item
#获取下一页地址
next_url = response.xpath("//a[@class='downPage']/@href").extract()

if next_url:
next_url = response.urljoin(next_url[0])
yield Request(next_url,callback=self.parse_image)


网上的方法也采取了，但是还是这个错误，请各位大神，给点指示性的意见

[敲出亿行bug]

问题解决了，大家有同样的问题，请参考我的博客
https://blog.csdn.net/wenquan19960602/article/details/104860522