Python+Selenium xpath定位—层级与逻辑组合定位

from  selenium import  webdriver
from time import sleep

driver=webdriver.Firefox()
driver.get("http://www.diwu.net/")
sleep(3)

#层级定位
driver.find_element_by_xpath("//form[@id='loginForm']/ul/input[1]").send_keys('diwu')
#组合定位
driver.find_element_by_xpath("//input[@class='loinp' and @name='username']").send_keys('diwu')
sleep(2)

driver.find_element_by_xpath("//form[@id='loginForm']/ul/input[2]").send_keys(6666)