关于Python selenium实现类似比价软件的功能

偶然间想实现比价的功能，正常requests途径比较难实现，于是乎想到可以selenium可以简易实现，下面是代码。

import requests
from selenium import webdriver
import json
import time
import threading

import matplotlib.pyplot as plt
import numpy as np

s = str(raw_input('请输入要比价内容：'))
print s
list = []

#京东价格，主要是selenium模拟，定位搜索框然后输入比价内容。其中还有error的处理。
def jd(s):
    driver = webdriver.Chrome()
    driver.get('https://www.jd.com/')
    driver.find_element_by_id('key').send_keys(s.decode('gbk'))
    driver.find_element_by_xpath('//*[@id="search"]/div/div[2]/button').click()
    time.sleep(2)
    try:
        print "京东价格：",driver.find_element_by_xpath('//*[@id="J_goodsList"]/ul/li[1]/div/div[3]/strong/i').text
        print "京东价格：",driver.find_element_by_xpath('//*[@id="J_goodsList"]/ul/li[1]/div/div[7]/span/a').text
        list.append(driver.find_element_by_xpath('//*[@id="J_goodsList"]/ul/li[1]/div/div[3]/strong/i').text)
    except:
        print "京东价格：",driver.find_element_by_xpath('//*[@id="J_goodsList"]/ul/li[1]/div/div[2]/strong/i').text
        print "京东价格：",driver.find_element_by_xpath('//*[@id="J_goodsList"]/ul/li[1]/div/div[5]/span/a').text
        list.append(driver.find_element_by_xpath('//*[@id="J_goodsList"]/ul/li[1]/div/div[2]/strong/i').text)
    finally:
        driver.quit()

#淘宝价格，跟京东类似
def taobao(s):
    driver = webdriver.Chrome()
    driver.get('https://www.taobao.com/')
    driver.find_element_by_id('q').send_keys(s.decode('gbk'))
    driver.find_element_by_xpath('//*[@id="J_TSearchForm"]/div[1]/button').click()
    time.sleep(2)
    try:
        print "淘宝价格：",driver.find_element_by_xpath('//*[@id="mainsrp-itemlist"]/div/div/div[1]/div[1]/div[2]/div[1]/div[1]/strong').text
        list.append(driver.find_element_by_xpath('//*[@id="mainsrp-itemlist"]/div/div/div[1]/div[1]/div[2]/div[1]/div[1]/strong').text)
    except:
        print "淘宝价格：",driver.find_element_by_xpath('//*[@id="J_itemlistListItem0"]/div[2]/p/a').text
        print "淘宝价格：",driver.find_element_by_xpath('//*[@id="J_itemlistListItem0"]/div[3]/div[1]/span/strong').text

        list.append(driver.find_element_by_xpath('//*[@id="J_itemlistListItem0"]/div[3]/div[1]/span/strong').text)
    finally:
        driver.quit()

#亚马逊价格
def amz(s):
    driver = webdriver.Chrome()
    driver.get('https://www.amazon.cn/')
    driver.find_element_by_id('twotabsearchtextbox').send_keys(s.decode('gbk'))
    driver.find_element_by_xpath('//*[@id="nav-search"]/form/div[2]/div/input').click()
    time.sleep(2)
    print "亚马逊价格：",driver.find_element_by_xpath('//*[@id="result_0"]/div/div[4]/div[1]/a/span[2]').text
    list.append(driver.find_element_by_xpath('//*[@id="result_0"]/div/div[4]/div[1]/a/span[2]').text.replace(',','')[1:])
    driver.quit()

#用到多线程处理。
threads = []
t1 = threading.Thread(target=jd,args=(s,))
threads.append(t1)
t2 = threading.Thread(target=taobao,args=(s,))
threads.append(t2)
t3 = threading.Thread(target=amz,args=(s,))
threads.append(t3)
for i in range(len(threads)):
    threads[i].start()
for i in range(len(threads)):
    threads[i].join()
print list

#图像展示
list = [int(i.split('.')[0]) for i in list]
index=np.arange(3)

plt.bar(left=index,height=list,width=0.5)
plt.xticks((0,1,2),('Jd','Taobao','Amazon'))
plt.show()

效果图：

简单的功能实现了，不足之处（有待改善）：

1、等待时间太长，体验不佳，即使多线程也要18s左右才能返回结果，太慢。

2、开3个webdriver，占用资源有点多，也导致比较慢。

3、错误处理未完善。