Python + Selenium + Pytest 自动化测试实战示例

Python + Selenium + Pytest 自动化测试实战示例

1. 环境准备

# 安装依赖库
pip install selenium pytest pytest-html webdriver-manager

2. 项目结构

automation_framework/
├── conftest.py
├── pages/
│   ├── __init__.py
│   └── login_page.py
├── tests/
│   ├── __init__.py
│   └── test_login.py
├── utils/
│   └── webdriver_factory.py
└── reports/ (自动生成)

3. 核心组件实现

a. 浏览器驱动管理 (utils/webdriver_factory.py)

from selenium import webdriver
from webdriver_manager.chrome import ChromeDriverManager
from webdriver_manager.firefox import GeckoDriverManager

class WebDriverFactory:
    @staticmethod
    def get_driver(browser="chrome"):
        if browser.lower() == "firefox":
            return webdriver.Firefox(
                executable_path=GeckoDriverManager().install()
            )
        else:
            return webdriver.Chrome(
                executable_path=ChromeDriverManager().install()
            )

b. Page Object 模式 (pages/login_page.py)

from selenium.webdriver.common.by import By
from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.support import expected_conditions as EC

class LoginPage:
    def __init__(self, driver):
        self.driver = driver
        self.url = "https://example.com/login"
        
    def open(self):
        self.driver.get(self.url)
        
    def enter_username(self, username):
        self.driver.find_element(By.ID, "username").send_keys(username)
        
    def enter_password(self, password):
        self.driver.find_element(By.ID, "password").send_keys(password)
        
    def click_login(self):
        self.driver.find_element(By.XPATH, "//button[@type='submit']").click()
        
    def get_error_message(self):
        return WebDriverWait(self.driver, 10).until(
            EC.visibility_of_element_located((By.CLASS_NAME, "error-message"))
        ).text

c. 测试配置 (conftest.py)

import pytest
from utils.webdriver_factory import WebDriverFactory

@pytest.fixture(scope="function")
def browser(request):
    driver = WebDriverFactory.get_driver()
    driver.maximize_window()
    yield driver
    driver.quit()

@pytest.fixture
def login_page(browser):
    page = LoginPage(browser)
    page.open()
    return page

4. 测试用例实现 (tests/test_login.py)

import pytest

class TestLogin:
    @pytest.mark.parametrize("username, password", [
        ("admin", "correct_password"),
        ("test_user", "valid_pass123")
    ])
    def test_valid_login(self, login_page, username, password):
        login_page.enter_username(username)
        login_page.enter_password(password)
        login_page.click_login()
        assert "Dashboard" in login_page.driver.title

    def test_invalid_password(self, login_page):
        login_page.enter_username("admin")
        login_page.enter_password("wrong_pass")
        login_page.click_login()
        assert "Invalid credentials" in login_page.get_error_message()

    def test_empty_fields(self, login_page):
        login_page.click_login()
        error_text = login_page.get_error_message()
        assert "Username is required" in error_text
        assert "Password is required" in error_text

5. 运行测试

# 执行所有测试并生成HTML报告
pytest --html=reports/report.html --self-contained-html

6. 测试报告示例

执行后将在 reports/ 目录生成交互式HTML报告：

• 包含通过/失败的测试用例统计
• 每个测试步骤的详细日志
• 失败用例的屏幕截图

7. 关键设计要点

1. 分层架构：

   • Page Object 封装页面交互
   • 测试用例专注业务逻辑验证
   • 驱动管理独立于测试逻辑

2. 参数化测试：

   @pytest.mark.parametrize("username, password", [
       ("user1", "pass1"),
       ("user2", "pass2")
   ])
   

3. 智能等待机制：

   WebDriverWait(driver, 10).until(
       EC.visibility_of_element_located((By.ID, "element"))
   )
   

4. 失败自动截图 (在 conftest.py 中添加)：

   @pytest.hookimpl(hookwrapper=True)
   def pytest_runtest_makereport(item, call):
       outcome = yield
       report = outcome.get_result()
       if report.when == "call" and report.failed:
           driver = item.funcargs["browser"]
           driver.save_screenshot(f"reports/screenshot_{item.name}.png")
   

8. 高级功能扩展

1. 跨浏览器测试：

   pytest --browser=firefox
   

2. API 集成测试：

   def test_login_api(api_client):
       response = api_client.post("/login", 
                                json={"username": "test", "password": "pass"})
       assert response.status_code == 200
       assert "auth_token" in response.json()
   

3. 持续集成配置 (Jenkinsfile 示例)：

   pipeline {
     agent any
     stages {
       stage('Test') {
         steps {
           sh 'pip install -r requirements.txt'
           sh 'pytest --html=report.html'
         }
         post {
           always {
             publishHTML target: [
               allowMissing: true,
               alwaysLinkToLastBuild: true,
               keepAll: true,
               reportDir: 'reports',
               reportFiles: 'report.html',
               reportName: 'HTML Report'
             ]
           }
         }
       }
     }
   }
   

最佳实践建议：

1. 使用 pytest-xdist 实现并行测试
2. 敏感数据（如密码）通过 .env 文件管理
3. 元素定位器统一管理在 locators.py 文件中
4. 添加 @pytest.mark.flaky(retries=2) 处理偶发失败
5. 使用 Allure 框架生成更专业的测试报告