python爬虫selenium-前程无忧

1.背景介绍

selenium通过驱动浏览器，模拟浏览器的操作，进而爬取数据。此外，还需要安装浏览器驱动，相关步骤自行解决。

思维导图：

2.导入库

import csv
import random
import time
from time import sleep
from selenium import webdriver
from selenium.webdriver import ActionChains
from selenium.webdriver import ChromeOptions
from selenium.webdriver.common.by import By

3.去除浏览器识别

option = ChromeOptions()
option.add_experimental_option('excludeSwitches', ['enable-automation'])
option.add_experimental_option('detach', True)

去除浏览器上方的“Chrome正受到自动测试软件的控制”字眼。

4.实例化一个浏览器对象（传入浏览器的驱动程序）

driver = webdriver.Chrome(options=option)

5. 发起请求

driver.get("https://www.51job.com/")
time.sleep(2) #防止加载缓慢，休眠2秒

6.解决特征识别

script = 'Object.defineProperty(navigator, "webdriver", {get: () => false,});'
driver.execute_script(script)

没有出现验证框或验证滑块，说明已经成功屏蔽selenium识别。

7.定位输入框并查找相关职位

driver.find_element(By.XPATH, '//*[@id="kwdselectid"]').click()
driver.find_element(By.XPATH, '//*[@id="kwdselectid"]').clear()
driver.find_element(By.XPATH, '//*[@id="kwdselectid"]').send_keys('老师')
driver.find_element(By.XPATH, '/html/body/div[3]/div/div[1]/div/button').click()
# driver.implicitly_wait(10)
time.sleep(5)
print(driver.current_url)

输入关键词“老师”，根据自我需要进行更改。

8.利用xpath和css选择器提取数据

jobData = driver.find_elements(By.XPATH, '//*[@id="app"]/div/div[2]/div/div/div[2]/div/div[2]/div/div[2]/div[1]/div')
    for job in jobData:
        jobName = job.find_element(By.CLASS_NAME, 'jname.at').text
        time.sleep(random.randint(5, 15) * 0.1)
        jobSalary = job.find_element(By.CLASS_NAME, 'sal').text
        time.sleep(random.randint(5, 15) * 0.1)
        jobCompany = job.find_element(By.CLASS_NAME, 'cname.at').text
        time.sleep(random.randint(5, 15) * 0.1)
        company_type_size = job.find_element(By.CLASS_NAME, 'dc.at').text
        time.sleep(random.randint(5, 15) * 0.1)
        company_status = job.find_element(By.CLASS_NAME, 'int.at').text
        time.sleep(random.randint(5, 15) * 0.1)
        address_experience_education = job.find_element(By.CLASS_NAME, 'd.at').text
        time.sleep(random.randint(5, 15) * 0.1)

        try:
            job_welf = job.find_element(By.CLASS_NAME, 'tags').get_attribute('title')
        except:
            job_welf = '无数据'
        time.sleep(random.randint(5, 15) * 0.1)

        update_date = job.find_element(By.CLASS_NAME, 'time').text
        time.sleep(random.randint(5, 15) * 0.1)

        print(jobName, jobSalary, jobCompany, company_type_size, company_status, address_experience_education, job_welf,
              update_date)

因为防止网站防爬，获取数据的同时，让程序休眠随机长度的时间。（根据自我需要设定合适的时间长度）

在工作福利提取过程中，有的职位并没有这一选项，所以对其try...except...

9.定位页面输入框并实现跳转

xpath定位页码输入框，输入页码，完成跳转。为了防止反爬，每一操作后对程序休眠随机长度的时间。

driver.find_element(By.XPATH, '//*[@id="jump_page"]').click()
    time.sleep(random.randint(10, 30) * 0.1)
    driver.find_element(By.XPATH, '//*[@id="jump_page"]').clear()
    time.sleep(random.randint(10, 40) * 0.1)
    driver.find_element(By.XPATH, '//*[@id="jump_page"]').send_keys(page)
    time.sleep(random.randint(10, 30) * 0.1)
    driver.find_element(By.XPATH,
                        '//*[@id="app"]/div/div[2]/div/div/div[2]/div/div[2]/div/div[3]/div/div/span[3]').click()

10.数据存储

将提取的数据保存进csv中，以追加写入的方式。

 with open('wuyou_teacher.csv', 'a', newline='') as csvfile:
            writer = csv.writer(csvfile)
            writer.writerow(
                [jobName, jobSalary, jobCompany, company_type_size, company_status, address_experience_education,
                 job_welf,
                 update_date])