使用python和scrapy进行身份验证的Web抓取-不符合计划

我刚刚开始涉猎python，目的是从网站上获取数据，我找到了一个关于网站身份验证的粗略教程，并制定了一个计划，但不幸的是，它没有按照tin上的说明进行操作。登录页面似乎没有填充用户名或密码，我希望有人能看看代码，也许能指出我哪里出了问题，并提供一些帮助。代码如下：-

from scrapy.spiders.init import InitSpider
from scrapy.http import Request, FormRequest
from scrapy.linkextractors.sgml import SgmlLinkExtractor
from scrapy.spiders import Rule

class controlantSpider(InitSpider):
    name = 'controlant'
    allowed_domains = ['controlant.com']
    login_page = 'https://grp.controlant.com/user/login?redirect=%2f'
    start_urls = ['https://grp.controlant.com/group',
                  'https://grp.controlant.com/webforms/Admin/Overview.aspx']

    rules = (
        Rule(SgmlLinkExtractor(allow=r'-\w+.html$'),
             callback='parse_item', follow=True),
    )

    def init_request(self):
        """This function is called before crawling starts."""
        return Request(url=self.login_page, callback=self.login)

    def login(self, response):
        """Generate a login request."""
        return FormRequest.from_response(response,
                    formdata={'username': 'username', 'password': 'password'},
                    callback=self.check_login_response)

    def check_login_response(self, response):
        """Check the response returned by a login request to see if we are
        successfully logged in.
        """
        if "Hi wessex@alliance" in response.body:
            self.log("Successfully logged in. Let's start crawling!")
            # Now the crawling can begin..
            self.initialized()
        else:
            self.log("Bad times :(")
            # Something went wrong, we couldn't log in, so nothing happens.

    def parse_item(self, response):
        filename = response.url.split("/")[-2] + '.html'
        with open(filename, 'wb') as f:
            f.write(response.body)