帮我写一个分层的ui自动化框架代码并标明注释

好的，以下是一个示例UI自动化框架代码，带有注释说明：

# 应用层
class LoginPage:
    def __init__(self, driver):
        self.driver = driver
        self.username_input = driver.find_element_by_id("username")
        self.password_input = driver.find_element_by_id("password")
        self.login_button = driver.find_element_by_id("login")

    def login(self, username, password):
        self.username_input.clear()
        self.username_input.send_keys(username)
        self.password_input.clear()
        self.password_input.send_keys(password)
        self.login_button.click()

class HomePage:
    def __init__(self, driver):
        self.driver = driver
        self.logout_button = driver.find_element_by_id("logout")

    def logout(self):
        self.logout_button.click()

# 测试脚本层
class TestLogin:
    def __init__(self, driver):
        self.driver = driver
        self.login_page = LoginPage(driver)
        self.home_page = None

    def test_success_login(self, username, password):
        self.login_page.login(username, password)
        self.home_page = HomePage(driver)
        assert "Welcome" in driver.page_source

    def test_failed_login(self, username, password):
        self.login_page.login(username, password)
        assert "Invalid username or password" in driver.page_source

    def test_logout(self):
        self.home_page.logout()
        assert "Login" in driver.page_source

# 操作层
class DriverFactory:
    def create_driver(self, browser_name):
        if browser_name == "chrome":
            return webdriver.Chrome()
        elif browser_name == "firefox":
            return webdriver.Firefox()
        else:
            raise ValueError("Invalid browser name")

# 工具层
class TestRunner:
    def run_tests(self, test_class, driver):
        test_instance = test_class(driver)
        test_methods = [getattr(test_instance, name) for name in dir(test_instance) if name.startswith("test")]
        for test_method in test_methods:
            test_method()
        driver.quit()

# 数据层
class TestData:
    USERNAME = "test"
    PASSWORD = "123456"

# 测试入口
if __name__ == "__main__":
    driver_factory = DriverFactory()
    driver = driver_factory.create_driver("chrome")
    test_runner = TestRunner()
    test_runner.run_tests(TestLogin, driver)

该框架使用了Page Object Model模式，将应用层抽象为页面类和元素类。测试脚本层使用了单元测试框架，每个测试方法以test开头，可以使用assert语句进行断言。操作层使用了Selenium WebDriver来与应用程序进行交互。工具层提供了TestRunner类来运行测试用例，DriverFactory类来创建WebDriver实例。数据层提供了TestData类来管理测试数据。

需要注意的是，以上代码仅供参考，需要根据实际需求进行修改和扩展。