通过selenium实现的京东商品爬取

from selenium import webdriver
from selenium.webdriver.common.by import By
from selenium.webdriver.support.ui import webdriverwait
from selenium.webdriver.support import expected_conditions as ec
from lxml import etree
import csv
import requests,re,time
#搜索的商品名称
shopname="Python设计模式"
#声明浏览器对象
browser=webdriver.Chrome()
browser.get("https://www.jd.com")
#查找节点
inputtext = browser.find_element_by_class_name('text')
#输入数据
inputtext.send_keys(shopname)
#提交
btn = browser.find_element_by_class_name('button')
btn.click()
#搜索后的页面
#显式等待
wait = webdriverwait(browser, 10)
wait.until(ec.title_contains(shopname))
with open(shopname+".csv",'a') as f:
    wr= csv.DictWriter(f,['name','price','shop'])
    wr.writeheader()
    while True:
        #判断是否为反爬虫机制窗体 是否正常
        if len(browser.window_handles)>1:
            handles=browser.window_handles[1]
            browser.switch_to_window(handles)
            browser.close()
        # 滚动条
        browser.execute_script("window.scrollTo(0, document.body.scrollHeight)")
        wait.until(ec.presence_of_element_located((By.CLASS_NAME, 'pn-next')))
        # 爬取内容
        html = etree.HTML(browser.page_source)
        # 读取每个商品
        shops = html.xpath('//div[contains(@class,"gl-i-wrap")]')
        # 下一页
        npage =html.xpath('//a[@class="pn-next disabled"]/em//text()')
        for shop in shops:
            name = shop.xpath('.//div[contains(@class,"p-name")]//em//text()')
            name = "".join(name)
            price = shop.xpath('.//div[contains(@class,"p-price")]//i//text()')
            price = "".join(price)
            sname = shop.xpath('.//div[contains(@class,"p-shop")]//a//@title')
            sname = "".join(sname)
            if sname.strip() == '':
                sname = "京东自营"
            wr.writerow({'name':name,'price':price,'shop':sname})

        if len(npage)>0:
            break
        try:
            pbtn = browser.find_element_by_class_name("pn-next")
            pbtn.click()
        except:
            pass

    browser.close()