下拉框一般处理是两次点击，第一次点击弹出下拉框，第二次点击操作元素。
（注释：有些下拉框是鼠标移动上去直接弹出的，我们可以使用方法move_to_element()来处理）
<html>
<body>
<select id="ShippingMethod" onchange="updateShipping(options[selectedIndex]);"
name="ShippingMethod">
<option value="12.51">UPS Next Day Air ==> $12.51</option>
<option value="11.61">UPS Next Day Air Saver ==> $11.61</option>
<option value="10.69">UPS 3 Day Select ==> $10.69</option>
<option value="9.03">UPS 2nd Day Air ==> $9.03</option>
<option value="8.34">UPS Ground ==> $8.34</option>
<option value="9.25">USPS Priority Mail Insured ==> $9.25</option>
<option value="7.45">USPS Priority Mail ==> $7.45</option>
<option value="3.20" selected="">USPS First Class ==> $3.20</option>
</select>
</body>
</html>
#coding = utf-8
from selenium import webdriver
import os,time
#Selenium 下拉框处理
#D:\chromedriver_win32\chromedriver.exe
class driver_1(object):
#定义一个对象
def __init__(self):
self.driver = webdriver.Chrome('D:\chromedriver_win32\chromedriver.exe')
def driver_alert(self):
file_path = 'file:///' + os.path.abspath('drop_down.html')
self.driver.get(file_path)
time.sleep(2)
#先定位到下拉框
m = self.driver.find_element_by_id('ShippingMethod')
#点击下拉框下的选项
m.find_element_by_xpath('//option[@value="10.69"]').click()
time.sleep(3)
#退出浏览器
self.driver.close()
if __name__ == "__main__":
a = driver_1()
a.driver_alert()
