如果手工启动chromedriver

    使用selenium模拟登陆网站时，有些网站会识别chrome driver里的json信息，从而判断是不是爬虫程序，做到反爬效果。（比如知乎）

下面说明下怎么手动启动chromedriver

1）、启动chrome

给开始菜单里的chrome或者桌面快捷方式，右键打开文件夹所在路径

2）打开dos，切到chrome路径，执行：chrome.exe --remote-debugging-port=9090（端口自定义），表示以debug模式启动，监听端口是9090

3）获取json，在启动前，需确保所有chrome实例已经关闭，否则会返回拒绝连接。

class ZhihuSpider(scrapy.Spider):
    name = 'zhihu_2'
    allowed_domains = ['zhihu.com']
    start_urls = ['http://zhihu.com/']

    headers = {
        "HOST": "www.zhihu.com",
        "Referer": "https://www.zhizhu.com",
        'User-Agent': "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/60.0.3112.113 Safari/537.36"
    }
    custom_settings = {
        "COOKIES_ENABLED": True,
        "HTTPERROR_ALLOWED_CODES" : [400]
    }

    def parse(self, response):
        from selenium import webdriver
        from scrapy.selector import Selector
        from selenium.webdriver.chrome.options import Options
        chrome_option = Options()
        chrome_option.add_argument("--disable-extensions")
        chrome_option.add_experimental_option("debuggerAddress","127.0.0.1:9090")
        project_dir = os.path.abspath(os.path.dirname(os.path.dirname(__file__)))

        chromedriver_dir = os.path.join(project_dir, "tools\chromedriver.exe")
        browser = webdriver.Chrome(
            executable_path=chromedriver_dir,chrome_options=chrome_option)

        browser.get("https://www.zhihu.com/signup?next=%2F")

        # 模拟登录知乎,选择登录选项
        info = response.xpath('//*[@id="root"]/div/main/div/div/div/div[2]/div[2]/span/text()')
        browser.find_element_by_xpath('//*[@id="root"]/div/main/div/div/div/div[2]/div[2]/span').click()
        # 输入账号//*div[@class='SignFlow-accountInput Input-wrapper']/input
        browser.find_element_by_xpath(
            '//*[@id="root"]/div/main/div/div/div/div[2]/div[1]/form/div[1]/div[2]/div[1]/input').send_keys(
            "656521736@qq.com")
        # 输入密码
        browser.find_element_by_xpath(
            '//*[@id="root"]/div/main/div/div/div/div[2]/div[1]/form/div[2]/div/div[1]/input').send_keys("*****")
        # 模拟登录知乎,点击登录按钮
         #//*[@id="root"]/div/main/div/div/div/div[2]/div[1]/form/button
        # browser.find_element_by_xpath('//*[@id="root"]/div/main/div/div/div/div[2]/div[1]/form/button').click()

    # def start_requests(self):
    #
        return [
            Request('https://www.zhihu.com/signup?next=%2F', headers=self.headers, encoding="utf-8", dont_filter=True, callback=self.parse)]

调用

webdriver.Chrome方法是，加上一个参数chrome_options即可