scrapy- after achieving user login function how to redirect to another page

Recently i am learning Scrapy. I would like to scrape zoominfo. I have written user_login function. But i could not redirect to the search page that achieves the data scraping. The url that i would like to redirect is http://ift.tt/1WELmNS

here's my code

#!/usr/bin/env python
# -*- coding:utf-8 -*-
import scrapy
from scrapy.selector import Selector
from scrapy.http import Request, FormRequest
from tutorial.items import TutorialItem


class LoginSpider(scrapy.Spider):
    name = 'zoominfo'
    login_page = ['http://ift.tt/23gHrqO']
    start_urls = [
    'http://ift.tt/1WELmNS',
    ]
    headers = {
        "Accept":"text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8",
        "Accept-Encoding":"gzip, deflate, br",
        "Accept-Language":"en-US,en;q=0.5",
        "Connectionc":"keep-alive",
        "User-Agent":"Mozilla/5.0 (Macintosh; Intel Mac OS X 10.12; rv:50.0) Gecko/20100101 Firefox/50.0",
        "Referer":"http://ift.tt/2iTS56k"
    }   
    def init_request(self):
        return Request(url=self.login_page, callback=self.login)

    def login(self, response):
        print "Preparing Login"
        return FormRequest.from_response(
            response,
            headers=self.headers,
            formdata={
            'username':username, 
            'password':password},
            callback=self.after_login,
            dont_filter = Ture,
        )

    def after_login(self, response):
        if username in response.body:
            self.log("Success")
            self.initialized()
        else:
            self.log("Bad times")

    def parse(self, response):
        base_url = 'http://ift.tt/1WELmNS'
        text = Selector(response)
        item = TutorialItem()
        item['title'] = text.xpath('//title/text()').extract()
        print {'title':item["title"]}
        request = Request(base_url, callback=self.parse)

The main output is below:

2017-01-09 16:52:58 [scrapy.core.engine] INFO: Spider opened
2017-01-09 16:52:59 [scrapy.extensions.logstats] INFO: Crawled 0 pages (at 0 pages/min), scraped 0 items (at 0 items/min)
2017-01-09 16:52:59 [scrapy.core.engine] DEBUG: Crawled (200) <GET http://ift.tt/2iUiC5B; (referer: None)
{'title': []}
2017-01-09 16:52:59 [scrapy.core.engine] INFO: Closing spider (finished)

Neither the output print "Preparing Login" not print the correct title. Hope someone could give me some hint.Really thanks a lot