scrapy 开发日志

2018.8.13 登陆知乎

1、配置scrapy调试

在工程文件下新建python文件夹main.py用于调试项目（当然还可以使用pdb进行调试）

main.py

from scrapy.cmdline import execute

import sys
import os

sys.path.append(os.path.dirname(os.path.abspath(__file__)))
execute(["scrapy", "crawl", "Buycar"])

2、设置robots为False

3、拿到xsrf

import requests
import http.cookiejar as cookielib
import re
from bs4 import BeautifulSoup


agent = "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/66.0.3359.139 Safari/537.36"
header = {
    "HOST": "www.zhihu.com",
    "Referer": "https://www.zhihu.com/",
    "User-Agent": agent #之间是短线短线！！！！，不是下划线
}


def get_xsrf():
    response = requests.get("https://www.zhihu.com", headers=header)   
    xsrf = response.request._cookies._cookies.get('.zhihu.com').get('/').get('_xsrf').value
   
get_xsrf()

  4、登陆全部代码：

import requests
import http.cookiejar
import re
session =requests.session()

agent = "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/66.0.3359.139 Safari/537.36"
header = {
    "HOST": "www.zhihu.com",
    "Referer": "https://www.zhihu.com/",
    "User-Agent": agent #之间是短线短线！！！！，不是下划线
}

def get_xsrf():
    response = requests.get('https://www.zhihu.com',headers =header)
    xsrf = response.request._cookies._cookies.get('.zhihu.com').get('/').get('_xsrf').value
    return xsrf

def zhihu_login(account,password):
    post_url = 'https://www.zhihu.com/login/phone_num'
    post_data = {
        '_xsrf':get_xsrf(),
        'phone':account,
        'password':password
    }
    response_text = session.post(post_url, data=post_data, headers=header)
    if response_text.status_code == 200:
        print('登陆成功')
    else:
        print('登陆失败')


zhihu_login('18328020353','*****')

一片关webdriver xpath的使用http://toolsqa.com/selenium-webdriver/choosing-effective-xpath/
https://blog.csdn.net/passionboyxie/article/details/28632965
获取属性值https://blog.csdn.net/xm_csdn/article/details/53390649 
dr = driver.find_element_by_id('tooltip')
dr.get_attribute('data-original-title')  #获取tooltip的内容

我们唯一确定的是文本'Profile'将始终包含在此图像的src中，因此我们可以在xpath中使用此提示，如下所示：  
web.find_element_by_xpath(".//*[@class='Login-content']/form/button/ img [contains（@src，'Profile'） ]").click()

常用查找方式

find_element_by_name

find_element_by_id

find_element_by_xpath

find_element_by_link_text

find_element_by_partial_link_text

find_element_by_tag_name

find_element_by_class_name

find_element_by_css_selector

5、处理知乎验证码

https://blog.csdn.net/sinat_37202005/article/details/54406105

https://www.imooc.com/article/35586

2018.08.15改写middleware

class JSMiddleware(object):
    def process_request(self, request, spider):
        web = webdriver.Chrome("E:/software/python3.6/chromedriver.exe")
        try:
            if spider.name == "DouyuImage":
                # self.web.get(request.url)
                web.get(request.url)
                time.sleep(3)
                body = web.page_source
                print("访问:{0}".format(request.url))
                print("^" * 50)
                return HtmlResponse(url=web.current_url, body=body, encoding="utf-8", request=request)
        except Exception as e:
            print(e)
            print("webdriver 失败")
            return None

2018.08.18

python 链接 mysql 的SQL语句中如果含有中文一定要用format

sql = 'select id from question where user = "{0}" and Q_title = "{1}"'.format(item['Q_user'],item['Q_title'])，一定要这样写，记住{0}外面是有引号滴，有引号!!!!!!!!