注意：模擬登陸時儿奶，必須保證settings.py里的 COOKIES_ENABLED (Cookies中間件) 處于開啟狀態(tài)

COOKIES_ENABLED = True 或 # COOKIES_ENABLED = False

策略一：直接POST數(shù)據(jù)（比如需要登陸的賬戶信息)

只要是需要提供post數(shù)據(jù)的眷射，就可以用這種方法镇辉。下面示例里post的數(shù)據(jù)是賬戶密碼：

# -*- coding: utf-8 -*-
import scrapy


class Renren1Spider(scrapy.Spider):
    name = "renren1"
    allowed_domains = ["renren.com"]

    def start_requests(self):
        url = 'http://www.renren.com/PLogin.do'
        # FormRequest 是Scrapy發(fā)送POST請求的方法
        yield scrapy.FormRequest(
                url = url,
                formdata = {"email" : "mr_mao_hacker@163.com", "password" : "axxxxxxxe"},
                callback = self.parse_page)

    def parse_page(self, response):
        with open("mao2.html", "w") as filename:
            filename.write(response.body)

策略二：標準的模擬登陸步驟

正統(tǒng)模擬登錄方法：
首先發(fā)送登錄頁面的get請求词身，獲取到頁面里的登錄必須的參數(shù)（比如說zhihu登陸界面的 _xsrf）
然后和賬戶密碼一起post到服務(wù)器厅目，登錄成功

# -*- coding: utf-8 -*-
import scrapy



class Renren2Spider(scrapy.Spider):
    name = "renren2"
    allowed_domains = ["renren.com"]
    start_urls = (
        "http://www.renren.com/PLogin.do",
    )

    # 處理start_urls里的登錄url的響應(yīng)內(nèi)容，提取登陸需要的參數(shù)（如果需要的話)
    def parse(self, response):
        # 提取登陸需要的參數(shù)
        #_xsrf = response.xpath("http://_xsrf").extract()[0]

        # 發(fā)送請求參數(shù)，并調(diào)用指定回調(diào)函數(shù)處理
        yield scrapy.FormRequest.from_response(
                response,
                formdata = {"email" : "mr_mao_hacker@163.com", "password" : "axxxxxxxe"},#, "_xsrf" = _xsrf},
                callback = self.parse_page
            )

    # 獲取登錄成功狀態(tài)损敷，訪問需要登錄后才能訪問的頁面
    def parse_page(self, response):
        url = "http://www.renren.com/422167102/profile"
        yield scrapy.Request(url, callback = self.parse_newpage)

    # 處理響應(yīng)內(nèi)容
    def parse_newpage(self, response):
        with open("xiao.html", "w") as filename:
            filename.write(response.body)

策略三：直接使用保存登陸狀態(tài)的Cookie模擬登陸

如果實在沒辦法了葫笼，可以用這種方法模擬登錄，雖然麻煩一點拗馒，但是成功率100%

# -*- coding: utf-8 -*-
import scrapy

class RenrenSpider(scrapy.Spider):
    name = "renren"
    allowed_domains = ["renren.com"]
    start_urls = (
        'http://www.renren.com/111111',
        'http://www.renren.com/222222',
        'http://www.renren.com/333333',
    )

    cookies = {
    "anonymid" : "ixrna3fysufnwv",
    "_r01_" : "1",
    "ap" : "327550029",
    "JSESSIONID" : "abciwg61A_RvtaRS3GjOv",
    "depovince" : "GW",
    "springskin" : "set",
    "jebe_key" : "f6fb270b-d06d-42e6-8b53-e67c3156aa7e%7Cc13c37f53bca9e1e7132d4b58ce00fa3%7C1484060607478%7C1%7C1486198628950",
    "t" : "691808127750a83d33704a565d8340ae9",
    "societyguester" : "691808127750a83d33704a565d8340ae9",
    "id" : "327550029",
    "xnsid" : "f42b25cf",
    "loginfrom" : "syshome"
    }

    # 可以重寫Spider類的start_requests方法路星，附帶Cookie值，發(fā)送POST請求
    def start_requests(self):
        for url in self.start_urls:
            yield scrapy.FormRequest(url, cookies = self.cookies, callback = self.parse_page)

    # 處理響應(yīng)內(nèi)容
    def parse_page(self, response):
        print "===========" + response.url
        with open("deng.html", "w") as filename:
            filename.write(response.body)