Selenium使用

《Flask Web开发》一书中提到使用Selenium进行端到端的测试，Selenium是一组多平台的浏览器自动化工具。我们这里主要使用WebDriver来模拟打开Chrome访问网页的功能。

安装

我们使用pip工具来安装selenium(Mac OS X)。
pip install selenium

同时安装Chrome驱动
brew install chromedriver，记下安装路径。

简单使用

我使用Selenium来访问http://qinf.github.io/，代码如下：

#!/usr/bin/env python
# encoding: utf-8

from selenium import webdriver
import os

chromedriver = "/usr/local/Cellar/chromedriver/2.18/bin/chromedriver" # chromedirver可执行文件路径
os.environ["webdriver.chrome.driver"] = chromedriver
driver = webdriver.Chrome(chromedriver)
# driver = webdriver.Safari()
driver.get('http://qinf.github.io')
print driver.title
driver.quit()

当然如果把selenium放到系统路径里面会简略好多，代码如下：

from selenium import webdriver

dirver = webdriver.Chrome()
driver.get('http://qinf.github.io')
print driver.title # 打印标题
driver.quit() # 退出

Selenium-WebDriver API 命令与操作

抓出网页

通过调用get来打开一个页面：
dirver.get('http://qinf.github.io')

定位UI元素

我可以通过WebDriver实例或者WebElement来定位一个UI元素。

通过id

找到下面的元素
<div id="myId">...</div>

element = driver.find_element_by_id("myId")
or
form selenium.webdriver.common.by import By
element = driver.find_element(by=By.ID, value="myId")

通过Class Name

<div class="cheese"><span>Cheddar</span></div><div class="cheese"><span>Gouda</span></div>
cheeses = driver.find_elements_by_class_name("cheese")
# or
from selenium.webdriver.common.by import By
cheeses = driver.find_elements(By.CLASS_NAME, "cheese")

通过Tag Name

<iframe src="..."></iframe>
frame = driver.find_element_by_tag_name("iframe")
# or
from selenium.webdriver.common.by import By
frame = driver.find_element(By.TAG_NAME, "iframe")

通过Name

<input name="cheese" type="text"/>
cheese = driver.find_element_by_name("cheese")
# or
from selenium.webdriver.common.by import By
cheese = driver.find_element(By.NAME, "cheese")

通过Link Text

<a href="http://www.google.com/search?q=cheese">cheese</a>>
cheese = driver.find_element_by_link_text("cheese")
# or
from selenium.webdriver.common.by import By
cheese = driver.find_element(By.LINK_TEXT, "cheese")

通过Partial Link Text

<a href="http://www.google.com/search?q=cheese">search for cheese</a>>
cheese = driver.find_element_by_partial_link_text("cheese")
# or
from selenium.webdriver.common.by import By
cheese = driver.find_element(By.PARTIAL_LINK_TEXT, "cheese")

通过CSS

<div id="food"><span class="dairy">milk</span><span class="dairy aged">cheese</span></div>
cheese = driver.find_element_by_css_selector("#food span.dairy.aged")
# or
from selenium.webdriver.common.by import By
cheese = driver.find_element(By.CSS_SELECTOR, "#food span.dairy.aged")

通过XPATH

<input type="text" name="example" />
<INPUT type="text" name="other" />
inputs = driver.find_elements_by_xpath("//input")
# or
from selenium.webdriver.common.by import By
inputs = driver.find_elements(By.XPATH, "//input")

通过JavaScript

# 获取页面上加载jQuery的
element = driver.execute_script("return $('.cheese')[0]")
# 获取页面上每个标签的输入元素
labels = driver.find_elements_by_tag_name("label")
inputs = driver.execute_script(
    "var labels = arguments[0], inputs = []; for (var i=0; i < labels.length; i++){" +
    "inputs.push(document.getElementById(labels[i].getAttribute('for'))); } return inputs;", labels)

用户输入

处理select复选框

# 找到页面中的第一个select，然后循环选中每个option
select = driver.find_element_by_tag_name("select")
allOptions = select.find_elements_by_tag_name("option")
for option in allOptions:
    print "Value is: " + option.get_attribute("value")
    option.click()
# 更高效的做法使用"Select"函数
# available since 2.12
from selenium.webdriver.support.ui import Select
select = Select(driver.find_element_by_tag_name("select"))
select.deselect_all() # 取消所有选择
select.select_by_visible_text("Edam") # 选择展示文本为Edam的复选框

submit操作

driver.find_element_by_id("submit").click()
or element.submit()

在Windows和Frames之间移动

# 在命名windows间跳转
<a href="somewhere.html" target="windowName">Click here to open a new window</a>
driver.switch_to.window("windowName")
# 迭代处理每个window
for handle in driver.window_handles:
    driver.switch_to.window(handle)
# frame之间跳转
driver.switch_to.frame("frameName")

弹出框

alert = dirver.switch_to.alert

历史

driver.forward() # 前进
driver.back() # 后退

Cookies

# 添加cookie
driver.add_cookie({'name':'key', 'value':'value'})
# 打印cookie
for cookie in driver.get_cookies():
    print '%s --> %s' % (cookie['name'], cookie['value'])
# 删除cookie
driver.delete_cookie('value')
driver.delete_all_cookies()

参考

Selenium Document