Downloading pictures with scrapy

问题

I'm starting with scrapy, and I have first real problem. It's downloading pictures. So this is my spider.

from scrapy.contrib.spiders import CrawlSpider, Rule
from scrapy.selector import HtmlXPathSelector
from scrapy.contrib.linkextractors.sgml import SgmlLinkExtractor
from example.items import ProductItem
from scrapy.utils.response import get_base_url

import re

class ProductSpider(CrawlSpider):
    name = "product"
    allowed_domains = ["domain.com"]
    start_urls = [
            "http://www.domain.com/category/supplies/accessories.do"
    ]

    def parse(self, response):
        hxs = HtmlXPathSelector(response)
        items = []
        sites = hxs.select('//td[@class="thumbtext"]')
        number = 0
        for site in sites:
            item = ProductItem()
            xpath = '//div[@class="thumb"]/img/@src'
            item['image_urls'] = site.select(xpath).extract()[number]
            item['image_urls'] = 'http://www.domain.com' + item['image_urls']
            items.append(item)
            number = number + 1
        return items

When I quote ITEM_PIPELINES and IMAGES_STORE in settings.py this way I get the proper URL for picture I want to download (copy pasted it into browser for check).

But when I unquote those i get following error:

raise ValueError('Missing scheme in request url: %s' % self._url')
exceptions.ValueError: Missing scheme in request url:h

and I can't download my pictures.

I've searched for the whole day and didn't find anything helpful.

回答1:

I think the image URL you scraped is relative. To construct the absolute URL use urlparse.urljoin:

def parse(self, response):
    ...
    image_relative_url = hxs.select("...").extract()[0]
    import urlparse
    image_absolute_url = urlparse.urljoin(response.url, image_relative_url.strip())
    item['image_urls'] = [image_absolute_url]
    ...

Haven't used ITEM_PIPELINES, but the docs say:

In a Spider, you scrape an item and put the URLs of its images into a image_urls field.

So, item['image_urls'] should be a list of image URLs. But your code has:

item['image_urls'] = 'http://www.domain.com' + item['image_urls']

So, i guess it iterates your single URL char by char - using each as URL.

回答2:

I think that you may need to provide your image url in a list to the Item:

item['image_urls'] = [ 'http://www.domain.com' + item['image_urls'] ]

来源：https://stackoverflow.com/questions/8773732/downloading-pictures-with-scrapy

标签

python

scrapy