djangolocal.py

from scrapy.spider import BaseSpider
from scrapy.http import FormRequest, Request
from scrapy.selector import HtmlXPathSelector

class DjangoSpider(BaseSpider):
    domain_name = "django.local"
    start_urls = ["http://localhost:8000/admin/"]
    extra_domain_names = ["localhost"]

    def parse(self, response):
        # log in into django's admin interface
        data = {'username': 'admin', 'password': 'admin'}
        return FormRequest.from_response(response,
                                         formdata=data,
                                         callback=self.after_login,
                                         dont_filter=True # because we will get
                                                          # redirected to same
                                                          # url and can be
                                                          # filtered out by
                                                          # dupesfilter
                                        )

    def after_login(self, response):
        if 'id="form_login"' in response.body:
            # login form displayed again, could not be able to login
            self.log("Username or password incorrect")
        else:
            # response is django's dashboard
            hxs = HtmlXPathSelector(response)
            # do stuff and/or return new requests


SPIDER = DjangoSpider()

Why can not find the param dont_filter in doc :https://scrapy.readthedocs.org/en/latest/topics/request-response.html