scrapy正在给出错误，没有属性'OP_SINGLE_ECDH_USE'

Question

当我使用Scrapy编写蜘蛛时，我不断收到错误：

AttributeError: 'module' object has no attribute 'OP_SINGLE_ECDH_USE'

这是我的代码：

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


class ZhihuSpider(scrapy.Spider):
    name = "zhihu"
    allowed_domains = ["www.zhihu.com"]
    start_urls = ["http://www.zhihu.com"]

    def start_requests(self):
        print '\n\n\n 1 \n\n\n'
        return [scrapy.Request('http://www.zhihu.com/#signin')]

    def parse(self, response):
        print '\n\n\n2\n\n\n'
        print response