selenium通过已知元素定位元素

# coding=utf-8

from selenium import webdriver

driver = webdriver.Chrome()
driver.get("http://www.baidu.com")
driver.maximize_window()
# 定位一个元素
positioned_element = driver.find_element_by_id("form")

# 通过已定位元素，定位子元素
child_element = positioned_element.find_element_by_xpath("span[2]/input")
child_element.send_keys("selenium")

# 通过已定位元素，定位兄弟元素
brother_element = positioned_element.find_element_by_xpath("../a/img[1]")
brother_attribute = brother_element.get_attribute("title")
print(brother_attribute)

# 通过已定位元素，定位其它层级元素
other_element = positioned_element.find_element_by_xpath("../../../div[3]/a[1]")
other_attribute = other_element.get_attribute("href")
print(other_attribute)