Python使用Selenium爬取淘宝异步加载的数据方法

            
#encoding:utf8
import re

from selenium import webdriver
from selenium.common.exceptions import TimeoutException

from selenium.webdriver.common.by import By
from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.support import expected_conditions as EC

from bs4 import BeautifulSoup
from config import *
import pymongo

client=pymongo.MongoClient(MONGODB_URL)
db=client[MONGODB_DB]


##这里使用PhantomJS，并配置了一些参数
browser=webdriver.PhantomJS(service_args=SERVICE_ArGS)

##窗口的大小，不设置的话，默认太小，会有问题
browser.set_window_size(1400,900)

wait=WebDriverWait(browser, 10)


def search():

  print('正在搜索')
##容易出现超时的错误
  try:
##等待这两个模块都加载好
    browser.get("https://www.taobao.com")
    input = wait.until(
        EC.presence_of_element_located((By.CSS_SELECTOR, '#q'))
      )
    submit=wait.until(
        EC.element_to_be_clickable((By.CSS_SELECTOR, '#J_TSearchForm > div.search-button > button'))
      )

    ######这块python2搞得鬼
    #input.send_keys('\u7f8e\u98df'.decode("unicode-escape"))
    input.send_keys(KEYWORD.decode("unicode-escape"))
    submit.click()

    total = wait.until(
        EC.presence_of_element_located((By.CSS_SELECTOR, '#mainsrp-pager > div > div > div > div.total'))
      )
    get_product()
    return total.text
  except TimeoutException:
    return search()

def next_page(page_number):

  print('翻页'+str(page_number))
  try:
    input = wait.until(
          EC.presence_of_element_located((By.CSS_SELECTOR, '#mainsrp-pager > div > div > div > div.form > input'))
        )
    submit=wait.until(
        EC.element_to_be_clickable((By.CSS_SELECTOR, '#mainsrp-pager > div > div > div > div.form > span.btn.J_Submit'))
      )

    input.clear()
    input.send_keys(page_number)
    submit.click()

##判断是否翻页成功 高亮的是不是输入的值，直接加在后面即可
    wait.until(EC.text_to_be_present_in_element((By.CSS_SELECTOR,'#mainsrp-pager > div > div > div > ul > li.item.active > span'),str(page_number)))

    get_product()

  except TimeoutException:
    return next_page(page_number)

#获取产品信息
def get_product():
  products = wait.until(
    EC.presence_of_element_located((By.CSS_SELECTOR, '#mainsrp-itemlist .m-itemlist .items'))
        )
##拿到网页
  html = browser.page_source
  soup = BeautifulSoup(html,'lxml')
  items = soup.select('#mainsrp-itemlist .m-itemlist .items .item.J_MouserOnverReq')#

  print('*************************到此*************')
  for item in items:
    img = item.select('.J_ItemPic.img')[0].get('src')
    price = item.select('.price.g_price.g_price-highlight > strong')[0].get_text()
    deal = item.select('.deal-cnt')[0].get_text()
    title= item.select('.row.row-2.title > a ')[0].get_text().strip() #:nth-of-type(3)
    shop = item.select('.row.row-3.g-clearfix > .shop > a > span:nth-of-type(2)')[0].get_text() 
    location = item.select('.location')[0].get_text()

    product={
      'img':img,
      'price':price,
      'deal':deal,
      'title':title,
      'shop':shop,
      'location':location
    }

#打印一下
    import json
    j = json.dumps(product)
    dict2 = j.decode("unicode-escape")
    print dict2

    save_to_mongo(product)


def save_to_mongo(product):
  try:
    if db[MONGODB_TABLE].insert(product):
      print('存储到mongodb成功'+str(product))
  except Exception:
    print("存储到mongodb失败"+str(product))



def main():

  try:
    total=search()

    ##搜寻 re正则表达式
    s=re.compile('(\d+)')
    total=int(s.search(total).group(1))
    for i in range(2,total+1):
      next_page(i)
  except Exception:
    print('出错')
  finally:
    browser.close()

if __name__ == '__main__':
  main()

          

            
MONGODB_URL='localhost'
MONGODB_DB='taobao'
MONGODB_TABLE='meishi'

SERVICE_ArGS=['--load-images=false','--disk-cache=true']

##就是美食这两个字，直接用汉字会报错
KEYWORD='\u7f8e\u98df'