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python - Missing scheme in request URL

I've been stuck on this bug for a while, the following error message is as follows:

File "C:Python27libsite-packagesscrapy-0.20.2-py2.7.eggscrapyhttp
equest\__init__.py", line 61, in _set_url
            raise ValueError('Missing scheme in request url: %s' % self._url)
            exceptions.ValueError: Missing scheme in request url: h

Scrapy code:

    from scrapy.contrib.spiders import CrawlSpider, Rule
    from scrapy.contrib.linkextractors.sgml import SgmlLinkExtractor
    from scrapy.selector import Selector
    from scrapy.http import Request
    from spyder.items import SypderItem

    import sys
    import MySQLdb
    import hashlib
    from scrapy import signals
    from scrapy.xlib.pydispatch import dispatcher

    # _*_ coding: utf-8 _*_

    class some_Spyder(CrawlSpider):
        name = "spyder"

        def __init__(self, *a, **kw):
            # catch the spider stopping
            # dispatcher.connect(self.spider_closed, signals.spider_closed)
            # dispatcher.connect(self.on_engine_stopped, signals.engine_stopped)

            self.allowed_domains = "domainname.com"
            self.start_urls = "http://www.domainname.com/"
            self.xpaths = '''//td[@class="CatBg" and @width="25%" 
                          and @valign="top" and @align="center"]
                          /table[@cellspacing="0"]//tr/td/a/@href'''

            self.rules = (
                Rule(SgmlLinkExtractor(restrict_xpaths=(self.xpaths))),
                Rule(SgmlLinkExtractor(allow=('cart.php?')), callback='parse_items'),
                )

            super(spyder, self).__init__(*a, **kw)

        def parse_items(self, response):
            sel = Selector(response)
            items = []
            listings = sel.xpath('//*[@id="tabContent"]/table/tr')

            item = IgeItem()
            item["header"] = sel.xpath('//td[@valign="center"]/h1/text()')

            items.append(item)
            return items

I'm pretty sure it's something to do with the URL I'm asking scrapy to follow in the LinkExtractor. When extracting them in shell they looking something like this:

data=u'cart.php?target=category&category_id=826'

Compared to another URL extracted from a working spider:

data=u'/path/someotherpath/category.php?query=someval'

I've had a look at a few questions on Stack Overflow, such as Downloading pictures with scrapy but from reading it I think I may have a slightly different problem.

I also took a look at this - http://static.scrapy.org/coverage-report/scrapy_http_request___init__.html

Which explains that the error is thrown up if self.URLs is missing a ":", from looking at the start_urls I've defined I can't quite see why this error would show since the scheme is clearly defined.

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by (71.8m points)

change start_urls to:

self.start_urls = ["http://www.bankofwow.com/"]

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