Python Selenium自动化测试PO设计模式实战

　　Page Object设计模式是自动化测试非常重要的一环，很多新入门自动化测试难以理解，先来看官网对PO说明：

1、设计原则

• The public methods represent the services that the page offers
• Try not to expose the internals of the page
• Generally don't make assertions
• Methods return other PageObjects
• Need not represent an entire page
• Different results for the same action are modelled as different methods

　　翻译如下：

　　公共方法表示页面提供的服务

　　不要暴露页面的细节

　　Page设计中不要出现断言，应该写在测试用例类中

　　方法应该返回其它的Page对象

　　不要去代表整个page

　　不同的结果返回不同的方法，不同的模式

从字面理解还是比较困难，我们继续看官网例子，官网例子为java

public class LoginPage {
    private final WebDriver driver;

    public LoginPage(WebDriver driver) {
        this.driver = driver;

        // Check that we're on the right page.
        if (!"Login".equals(driver.getTitle())) {
            // Alternatively, we could navigate to the login page, perhaps logging out first
            throw new IllegalStateException("This is not the login page");
        }
    }

    // The login page contains several HTML elements that will be represented as WebElements.
    // The locators for these elements should only be defined once.
        By usernameLocator = By.id("username");
        By passwordLocator = By.id("passwd");
        By loginButtonLocator = By.id("login");

    // The login page allows the user to type their username into the username field
    public LoginPage typeUsername(String username) {
        // This is the only place that "knows" how to enter a username
        driver.findElement(usernameLocator).sendKeys(username);

        // Return the current page object as this action doesn't navigate to a page represented by another PageObject
        return this;    
    }

    // The login page allows the user to type their password into the password field
    public LoginPage typePassword(String password) {
        // This is the only place that "knows" how to enter a password
        driver.findElement(passwordLocator).sendKeys(password);

        // Return the current page object as this action doesn't navigate to a page represented by another PageObject
        return this;    
    }

    // The login page allows the user to submit the login form
    public HomePage submitLogin() {
        // This is the only place that submits the login form and expects the destination to be the home page.
        // A seperate method should be created for the instance of clicking login whilst expecting a login failure. 
        driver.findElement(loginButtonLocator).submit();

        // Return a new page object representing the destination. Should the login page ever
        // go somewhere else (for example, a legal disclaimer) then changing the method signature
        // for this method will mean that all tests that rely on this behaviour won't compile.
        return new HomePage(driver);    
    }

    // The login page allows the user to submit the login form knowing that an invalid username and / or password were entered
    public LoginPage submitLoginExpectingFailure() {
        // This is the only place that submits the login form and expects the destination to be the login page due to login failure.
        driver.findElement(loginButtonLocator).submit();

        // Return a new page object representing the destination. Should the user ever be navigated to the home page after submiting a login with credentials 
        // expected to fail login, the script will fail when it attempts to instantiate the LoginPage PageObject.
        return new LoginPage(driver);    
    }

    // Conceptually, the login page offers the user the service of being able to "log into"
    // the application using a user name and password. 
    public HomePage loginAs(String username, String password) {
        // The PageObject methods that enter username, password & submit login have already defined and should not be repeated here.
        typeUsername(username);
        typePassword(password);
        return submitLogin();
    }
}

以上学习依然费劲，下面我们以登录为例，用PageObject模式开发脚本：

login.py  登录类Page

#_*_coding:utf-8_*_
#大牛测试
#qq:2574674466
#2574674466@qq.com

class loginPage(base):
　　#对用户名元素封装
    def username(self):
        return self.by_id("nloginname")
    #对密码元素封装
    def passwd(self):
        return  self.by_id("npwd")
    #对登录按钮封装
    def btn(self):
        return  self.by_id("nsubmit")
    #对登录方法封装
    def LoginIn(self,username,passwd):
        self.username().send_keys(username)
        self.passwd().send_keys(passwd)
        self.btn().click()

base.py  基类封装，

#_*_coding:utf-8_*_
#大牛测试
#qq:2574674466
#2574674466@qq.com

class base():
    def __init__(self,driver):
        self.driver = driver
     #id定位
    def by_id(self,element):
        return  self.driver.find_element_by_id(element)
    #name定位
    def by_name(self,element):
        return self.driver.find_element_by_name(element)
    #xpath定位
    def by_xpath(self,element):
        return  self.driver.find_element_by_xpath(element)

loginTest.py  登录测试类

#_*_coding:utf-8_*_
#大牛测试
#qq:2574674466
#2574674466@qq.com


class logingTest(unittest.TestCase):

    def setUp(self):
      #初始化
        self.driver = webdriver.Chrome(path)

    def test_01(self):
        lo=loginPage(self.driver)
        l=lo.LoginIn("","")

    def tearDown(self):
      #执行完成后退出
       self.driver.quit()


if __name__ == '__main__':
     unittest.main()