Selenium实例学习

安装selenium

pip install selenium

下载驱动(chromedriver)

下载前需要确认适配自己的浏览器版本

https://chromedriver.storage.googleapis.com/index.html

selenium的基本用法

基本用法看官方文档，讲述的很清楚了，推荐

https://selenium-python.readthedocs.io/installation.html

常用的实例

设置浏览器不加载图片

from selenium import webdriver
# 设置不加载图片
chrome_opt = webdriver.ChromeOptions()
prefs = {
    "profile.managed_default_content_settings.images": 2
}

chrome_opt.add_experimental_option("prefs", prefs)

driver = webdriver.Chrome(chrome_options=chrome_opt)

driver.get("https://www.taobao.com")

点击弹窗与点击下拉列表

from selenium import webdriver
from selenium.webdriver.support.select import Select
driver = webdriver.Chrome()
# 点击接受弹窗
driver.switch_to.alert.accept()

# 点击下拉列表
sel = driver.find_element_by_id("nr")
Select(sel).select_by_index(2)

切换窗口

from selenium import webdriver
driver = webdriver.Chrome()

first_win = driver.current_window_handle

all_win = driver.current_window_handle

for win in all_win:
    if win != first_win:
        driver.switch_to.window(win)

自动下拉列表(以开源中国的博客栏目为例)

很多页面是下拉加载更多信息，我们如何模拟这个下拉操作：

from selenium import webdriver
import time

driver = webdriver.Chrome()

driver.get('https://www.oschina.net/blog')

time.sleep(5)
# 实现自动下拉刷新 下拉三页
for i in range(3):
    driver.execute_script('window.scrollTo(0,document.body.scrollHeight); var lenOfPage=document.body.scrollHeight; return lenOfPage;')
    time.sleep(3)

如何模拟手机访问？

from selenium import webdriver
# 模拟手机
mobilesetting = {"deviceName":"iPhone 6 Plus"}

options = webdriver.ChromeOptions()

options.add_experimental_option("mobileEmulation", mobilesetting)

driver = webdriver.Chrome(chrome_options=options)
# 设置大小
driver.set_window_size(400, 800)

# driver.maximize_window()
driver.get("https://www.taobao.com")
# 后退
driver.back()
# 前进
driver.forward()
# 刷新
driver.refresh()

如何为selenium设置代理？(连接无用户名密码认证的代理)

# 设置代理
from selenium import webdriver
options = webdriver.ChromeOptions()
options.add_argument("--proxy-server=http://ip:port")
driver = webdriver.Chrome(chrome_options=options)
driver.get("http://httpbin.org/ip")
print(driver.page_source)

如何为selenium设置代理？(有用户名和密码的连接)

推荐几篇文章：

https://www.cnblogs.com/roystime/p/6935543.html
https://stackoverflow.com/questions/29983106/how-can-i-set-proxy-with-authentication-in-selenium-chrome-web-driver-using-pyth#answer-30953780
https://cuiqingcai.com/4880.html

scrapy + selenium 模拟登录csdn

其实，没啥技术含量。只是简单运用，敲一遍加深印象。

spider.py

# -*- coding: utf-8 -*-
import scrapy
from selenium import webdriver

class CsdnSpider(scrapy.Spider):
    name = 'csdn'
    allowed_domains = ['csdn.net']
    start_urls = ['https://passport.csdn.net/account/login','https://i.csdn.net/#/account/index']

    def __init__(self):
        # mobilsetting = {"deviceName":"iPhone 6 Plus"}
        # options = webdriver.ChromeOptions()
        # options.add_experimental_option("mobileEmulation", mobilsetting)
        self.browser = None
        self.cookies = None
        # self.browser.set_window_size(400,800)
        super(CsdnSpider, self).__init__()
    def spider_closed(self, response):
        print("spider close")
        self.brower.close()


    def parse(self, response):
        print(response.url)
        print(response.body.decode("utf-8","ignore"))

middlewares.py

from scrapy import signals
from selenium import webdriver
from scrapy.http import HtmlResponse
import time
import requests
class LoginMiddleware(object):
    def process_request(self, request, spider):
        if spider.name == "csdn":
            if request.url.find("login") != -1:
                spider.browser = webdriver.Chrome()
                spider.browser.get(request.url)
                switch = spider.browser.find_element_by_xpath('//a[@class="login-code__open js_login_trigger login-user__active"]')
                if switch.text == '账号登录':
                    switch.click()
                time.sleep(3)
                username = spider.browser.find_element_by_id('username')
                password = spider.browser.find_element_by_id('password')
                time.sleep(2)
                username.send_keys("")
                time.sleep(1)
                password.send_keys("")
                time.sleep(2)
                click = spider.browser.find_element_by_class_name("logging")
                time.sleep(2)
                click.click()
                time.sleep(8)
                spider.cookies = spider.browser.get_cookies()
                return HtmlResponse(
                    url=spider.browser.current_url,
                    body=spider.browser.page_source,
                    encoding="utf-8"
                )
            else:
                req = requests.session()
                for cookie in spider.cookies:
                    req.cookies.set(cookie['name'], cookie['value'])
                req.headers.clear()
                newpage = req.get(request.url)
                print(request.url)
                print(newpage.text)
                return HtmlResponse(
                    url=request.url,
                    body=newpage.text,
                    encoding="utf-8"
                )