Selenium 自动化测试入门：从环境搭建到写出第一个可维护用例

pip install selenium

from selenium import webdriver

driver = webdriver.Chrome()
driver.get("https://www.example.com")
print(driver.title)
driver.quit()

from selenium.webdriver.chrome.service import Service

service = Service("/path/to/chromedriver")
driver = webdriver.Chrome(service=service)

from selenium import webdriver
from selenium.webdriver.common.by import By
from selenium.webdriver.common.keys import Keys

driver = webdriver.Chrome()

try:
    # 1. 打开目标页面
    driver.get("https://www.example.com")

    # 2. 找到搜索框，输入关键词
    search_box = driver.find_element(By.NAME, "q")
    search_box.clear()
    search_box.send_keys("selenium testing")

    # 3. 提交搜索
    search_box.send_keys(Keys.RETURN)

    # 4. 简单验证：页面标题是否包含搜索词
    assert "selenium" in driver.title.lower(), "搜索结果页标题不符合预期"
    print("测试通过")

except Exception as e:
    print(f"测试失败: {e}")

finally:
    driver.quit()

driver.implicitly_wait(10)  # 全局生效，最多等 10 秒

from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.support import expected_conditions as EC

wait = WebDriverWait(driver, 10)

# 等待某个元素可点击
button = wait.until(EC.element_to_be_clickable((By.ID, "submit-btn")))
button.click()

# 等待某个元素出现在 DOM 中
result = wait.until(EC.presence_of_element_located((By.CSS_SELECTOR, ".result-item")))

driver.find_element(By.ID, "username")

# 类名定位
driver.find_element(By.CSS_SELECTOR, ".login-form .submit-btn")

# 属性定位
driver.find_element(By.CSS_SELECTOR, "input[data-testid='email']")

# 层级定位
driver.find_element(By.CSS_SELECTOR, "div.container > ul > li:first-child")

# 按文本内容找按钮
driver.find_element(By.XPATH, "//button[text()='提交']")

# 按部分文本匹配
driver.find_element(By.XPATH, "//span[contains(text(), '搜索结果')]")

# 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:
    URL = "https://www.example.com/login"

    # 元素定位器集中管理
    USERNAME_INPUT = (By.ID, "username")
    PASSWORD_INPUT = (By.ID, "password")
    SUBMIT_BUTTON = (By.CSS_SELECTOR, "button[type='submit']")
    ERROR_MESSAGE = (By.CSS_SELECTOR, ".error-msg")

    def __init__(self, driver):
        self.driver = driver
        self.wait = WebDriverWait(driver, 10)

    def open(self):
        self.driver.get(self.URL)
        return self

    def login(self, username, password):
        self.wait.until(EC.visibility_of_element_located(self.USERNAME_INPUT))
        self.driver.find_element(*self.USERNAME_INPUT).clear()
        self.driver.find_element(*self.USERNAME_INPUT).send_keys(username)
        self.driver.find_element(*self.PASSWORD_INPUT).clear()
        self.driver.find_element(*self.PASSWORD_INPUT).send_keys(password)
        self.driver.find_element(*self.SUBMIT_BUTTON).click()

    def get_error_message(self):
        error = self.wait.until(
            EC.visibility_of_element_located(self.ERROR_MESSAGE)
        )
        return error.text

# tests/test_login.py
import pytest
from selenium import webdriver
from pages.login_page import LoginPage


@pytest.fixture
def driver():
    d = webdriver.Chrome()
    yield d
    d.quit()


def test_invalid_login_shows_error(driver):
    page = LoginPage(driver).open()
    page.login("wrong_user", "wrong_pass")
    assert "用户名或密码错误" in page.get_error_message()


def test_empty_password_shows_error(driver):
    page = LoginPage(driver).open()
    page.login("some_user", "")
    assert "请输入密码" in page.get_error_message()

pip install pytest

project/
├── pages/              # Page Object 类
│   ├── login_page.py
│   └── home_page.py
├── tests/              # 测试用例
│   ├── conftest.py     # 公共 fixture（比如 driver 初始化）
│   ├── test_login.py
│   └── test_search.py
└── pytest.ini          # pytest 配置

# tests/conftest.py
import pytest
from selenium import webdriver


@pytest.fixture
def driver():
    options = webdriver.ChromeOptions()
    # 无头模式，CI 环境常用
    # options.add_argument("--headless")
    d = webdriver.Chrome(options=options)
    d.maximize_window()
    yield d
    d.quit()

pytest tests/ -v

driver.execute_script("arguments[0].click();", element)

driver.switch_to.frame("frame-name")
# 操作完再切回主文档
driver.switch_to.default_content()

# 获取所有窗口句柄
handles = driver.window_handles
# 切到最新打开的
driver.switch_to.window(handles[-1])

from selenium.webdriver.support.ui import Select

dropdown = Select(driver.find_element(By.ID, "country"))
dropdown.select_by_visible_text("中国")
# 或者
dropdown.select_by_value("CN")

options = webdriver.ChromeOptions()
options.add_argument("--headless=new")
options.add_argument("--no-sandbox")
options.add_argument("--disable-dev-shm-usage")
driver = webdriver.Chrome(options=options)

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

options.add_argument("--window-size=1920,1080")