Python Selenium 完全指南：從入門到精通

📚 目錄

1. 環境準備與基礎入門
2. 元素定位與交互操作
3. 等待機制與異常處理
4. 面向對象封裝與框架設計
5. 進階技巧與最佳實踐
6. 性能優化與調試技巧
7. 實戰案例分析

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環境準備與基礎入門

1. 安裝 Selenium 與瀏覽器驅動

安裝 Selenium

# 使用pip安裝最新版本
pip install selenium# 安裝特定版本
pip install selenium==4.10.0# 在虛擬環境中安裝(推薦)
python -m venv selenium_env
source selenium_env/bin/activate  # Linux/Mac
selenium_env\Scripts\activate.bat  # Windows
pip install selenium

安裝瀏覽器驅動

從Selenium 4.0開始，提供了自動管理驅動的功能，但了解手動安裝方法仍然很重要：

Chrome瀏覽器:

• 訪問 ChromeDriver 下載頁面
• 下載與本地Chrome版本匹配的驅動程序
• 將驅動添加到系統PATH中或在代碼中指定路徑

Firefox瀏覽器:

• 訪問 GeckoDriver 下載頁面
• 下載適用于你操作系統的版本
• 將驅動添加到系統PATH中或在代碼中指定路徑

Edge瀏覽器:

• 訪問 Microsoft Edge Driver 下載頁面
• 下載與本地Edge版本匹配的驅動程序

Safari瀏覽器:

• Safari驅動已內置于macOS中
• 需要在Safari瀏覽器中啟用開發者模式

2. Selenium 4.x 新特性

Selenium 4.x引入了許多重要的改進和新功能：

• 相對定位器：允許基于其他元素的位置來查找元素
• Service對象：用于更好地管理驅動程序服務
• WebDriver Manager：自動管理驅動程序的下載和設置
• CDP(Chrome DevTools Protocol)支持：允許訪問瀏覽器特定的功能

3. WebDriver初始化方法

使用Selenium Manager(推薦，Selenium 4.x)

from selenium import webdriver
from selenium.webdriver.chrome.service import Service# 自動管理驅動
driver = webdriver.Chrome()

傳統方法(指定驅動路徑)

from selenium import webdriver
from selenium.webdriver.chrome.service import Service# 指定驅動路徑
service = Service(executable_path='/path/to/chromedriver')
driver = webdriver.Chrome(service=service)

配置瀏覽器選項

from selenium import webdriver
from selenium.webdriver.chrome.options import Options# 創建Chrome選項對象
chrome_options = Options()
chrome_options.add_argument("--headless")  # 無頭模式
chrome_options.add_argument("--window-size=1920,1080")  # 設置窗口大小
chrome_options.add_argument("--disable-gpu")  # 禁用GPU加速
chrome_options.add_argument("--disable-extensions")  # 禁用擴展
chrome_options.add_argument("--proxy-server='direct://'")  # 代理設置
chrome_options.add_argument("--proxy-bypass-list=*")  # 繞過代理
chrome_options.add_argument("--start-maximized")  # 啟動時最大化窗口
chrome_options.add_experimental_option("prefs", {"download.default_directory": "/path/to/download/directory",  # 設置下載目錄"download.prompt_for_download": False,  # 禁用下載提示"download.directory_upgrade": True,"safebrowsing.enabled": True
})# 初始化WebDriver
driver = webdriver.Chrome(options=chrome_options)

4. 基礎瀏覽器操作

from selenium import webdriver# 初始化WebDriver
driver = webdriver.Chrome()# 窗口操作
driver.maximize_window()  # 最大化窗口
driver.set_window_size(1920, 1080)  # 設置窗口大小
driver.set_window_position(0, 0)  # 設置窗口位置# 導航操作
driver.get('https://www.example.com')  # 打開URL
driver.back()  # 后退
driver.forward()  # 前進
driver.refresh()  # 刷新頁面# 頁面信息
title = driver.title  # 獲取頁面標題
url = driver.current_url  # 獲取當前URL
page_source = driver.page_source  # 獲取頁面源代碼# Cookie操作
driver.add_cookie({"name": "key", "value": "value"})  # 添加Cookie
cookies = driver.get_cookies()  # 獲取所有Cookies
driver.delete_cookie("key")  # 刪除特定Cookie
driver.delete_all_cookies()  # 刪除所有Cookies# 關閉操作
driver.close()  # 關閉當前標簽頁
driver.quit()  # 關閉瀏覽器，釋放資源

5. 常見瀏覽器配置

無頭模式(Headless)

from selenium import webdriver
from selenium.webdriver.chrome.options import Optionschrome_options = Options()
chrome_options.add_argument("--headless")
driver = webdriver.Chrome(options=chrome_options)

使用代理

from selenium import webdriver
from selenium.webdriver.chrome.options import Optionschrome_options = Options()
chrome_options.add_argument('--proxy-server=http://proxyserver:port')
driver = webdriver.Chrome(options=chrome_options)

禁用圖片加載(提高性能)

from selenium import webdriver
from selenium.webdriver.chrome.options import Optionschrome_options = Options()
prefs = {"profile.managed_default_content_settings.images": 2}
chrome_options.add_experimental_option("prefs", prefs)
driver = webdriver.Chrome(options=chrome_options)

---

元素定位與交互操作

1. 元素定位基礎

Selenium提供了多種定位元素的方法，每種都有其適用場景：

from selenium import webdriver
from selenium.webdriver.common.by import Bydriver = webdriver.Chrome()
driver.get("https://www.example.com")# 1. 通過ID定位(最推薦，高效且唯一)
element = driver.find_element(By.ID, "login-button")# 2. 通過Name屬性定位
element = driver.find_element(By.NAME, "username")# 3. 通過Class Name定位(不唯一時返回第一個匹配元素)
element = driver.find_element(By.CLASS_NAME, "login-form")# 4. 通過Tag Name定位
element = driver.find_element(By.TAG_NAME, "button")# 5. 通過Link Text定位(完全匹配)
element = driver.find_element(By.LINK_TEXT, "Forgot Password?")# 6. 通過Partial Link Text定位(部分匹配)
element = driver.find_element(By.PARTIAL_LINK_TEXT, "Forgot")# 7. 通過CSS選擇器定位(強大且靈活)
element = driver.find_element(By.CSS_SELECTOR, "#login-form .submit-button")# 8. 通過XPath定位(最強大但可能較慢)
element = driver.find_element(By.XPATH, "//div[@id='login-form']//button")

2. 高級定位策略

XPath進階用法

# 絕對路徑(從根節點開始)
element = driver.find_element(By.XPATH, "/html/body/div/form/input")# 相對路徑(從任意節點開始)
element = driver.find_element(By.XPATH, "//input[@name='username']")# 使用contains()函數
element = driver.find_element(By.XPATH, "//button[contains(@class, 'login')]")# 使用text()函數
element = driver.find_element(By.XPATH, "//a[text()='Forgot Password?']")
element = driver.find_element(By.XPATH, "//a[contains(text(), 'Forgot')]")# 使用AND和OR操作符
element = driver.find_element(By.XPATH, "//input[@type='text' and @name='username']")
element = driver.find_element(By.XPATH, "//button[@type='submit' or @type='button']")# 通過父子關系定位
element = driver.find_element(By.XPATH, "//form[@id='login-form']/input")
parent = driver.find_element(By.XPATH, "//input[@id='username']/..")# 通過兄弟關系定位
element = driver.find_element(By.XPATH, "//input[@id='username']/following-sibling::input")
element = driver.find_element(By.XPATH, "//input[@id='password']/preceding-sibling::input")# 按索引定位
element = driver.find_element(By.XPATH, "(//input[@type='text'])[2]")# 使用軸(axes)
element = driver.find_element(By.XPATH, "//input[@id='username']/ancestor::form")
element = driver.find_element(By.XPATH, "//form/descendant::input")

CSS選擇器進階用法

# 基本選擇器
element = driver.find_element(By.CSS_SELECTOR, "#login-button")  # ID選擇器
element = driver.find_element(By.CSS_SELECTOR, ".login-form")    # Class選擇器
element = driver.find_element(By.CSS_SELECTOR, "input")          # 標簽選擇器# 屬性選擇器
element = driver.find_element(By.CSS_SELECTOR, "input[name='username']")
element = driver.find_element(By.CSS_SELECTOR, "input[name^='user']")  # 以user開頭
element = driver.find_element(By.CSS_SELECTOR, "input[name$='name']")  # 以name結尾
element = driver.find_element(By.CSS_SELECTOR, "input[name*='erna']")  # 包含erna# 組合選擇器
element = driver.find_element(By.CSS_SELECTOR, "form input[type='text']")
element = driver.find_element(By.CSS_SELECTOR, "form > input")  # 直接子元素
element = driver.find_element(By.CSS_SELECTOR, "label + input")  # 緊鄰兄弟元素
element = driver.find_element(By.CSS_SELECTOR, "label ~ input")  # 通用兄弟元素# 偽類選擇器
element = driver.find_element(By.CSS_SELECTOR, "input:first-child")
element = driver.find_element(By.CSS_SELECTOR, "input:last-child")
element = driver.find_element(By.CSS_SELECTOR, "input:nth-child(2)")

相對定位器(Selenium 4.x新特性)

from selenium.webdriver.support.relative_locator import locate_with# 獲取參考元素
username_field = driver.find_element(By.ID, "username")# 使用相對定位器
password_field = driver.find_element(locate_with(By.TAG_NAME, "input").below(username_field))
login_button = driver.find_element(locate_with(By.TAG_NAME, "button").below(password_field))
remember_me = driver.find_element(locate_with(By.TAG_NAME, "input").to_right_of(password_field))
forgot_password = driver.find_element(locate_with(By.TAG_NAME, "a").above(login_button))

3. 查找多個元素

# 查找所有符合條件的元素
elements = driver.find_elements(By.CSS_SELECTOR, ".product-item")# 遍歷元素列表
for element in elements:name = element.find_element(By.CLASS_NAME, "product-name").textprice = element.find_element(By.CLASS_NAME, "product-price").textprint(f"產品名稱: {name}, 價格: {price}")

4. 元素交互操作

# 輸入操作
element.send_keys("test@example.com")  # 輸入文本
element.send_keys(Keys.CONTROL, 'a')   # 鍵盤組合鍵(全選)
element.send_keys(Keys.BACK_SPACE)     # 退格鍵# 點擊操作
element.click()                        # 點擊元素
element.submit()                       # 提交表單(適用于表單元素內)# 清除操作
element.clear()                        # 清除文本輸入框# 獲取元素屬性和狀態
value = element.get_attribute("value")  # 獲取屬性值
text = element.text                     # 獲取元素文本內容
tag = element.tag_name                  # 獲取標簽名
size = element.size                     # 獲取元素大小
location = element.location             # 獲取元素位置
is_enabled = element.is_enabled()       # 元素是否啟用
is_selected = element.is_selected()     # 元素是否選中(復選框、單選按鈕等)
is_displayed = element.is_displayed()   # 元素是否可見# 特殊元素操作
# 下拉菜單
from selenium.webdriver.support.select import Select
select = Select(driver.find_element(By.ID, "dropdown"))
select.select_by_visible_text("Option 1")  # 通過文本選擇
select.select_by_value("option1")         # 通過值選擇
select.select_by_index(1)                 # 通過索引選擇
options = select.options                  # 獲取所有選項
first_option = select.first_selected_option  # 獲取當前選中選項
select.deselect_all()                      # 取消所有選擇(多選下拉框)# 復選框和單選按鈕
checkbox = driver.find_element(By.ID, "checkbox")
if not checkbox.is_selected():checkbox.click()

5. 元素查找最佳實踐

1. 性能優化順序：ID > Name > CSS > XPath
2. 避免使用：
   • 絕對XPath路徑(容易失效)
   • 基于視覺位置的選擇器
   • 多級嵌套CSS選擇器
3. 推薦使用：
   • 有意義的ID和名稱屬性
   • 數據測試屬性(如data-testid)
   • 短而明確的CSS選擇器
4. 建議添加：
   • 頁面加載和元素的等待機制
   • 查找元素的超時和重試機制
   • 詳細的錯誤處理機制

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等待機制與異常處理

1. 等待策略

在Web自動化中，頁面加載和元素渲染需要時間，等待機制至關重要。

隱式等待(Implicit Wait)

# 設置隱式等待時間(全局設置)
driver.implicitly_wait(10)  # 等待最多10秒直到元素出現

隱式等待會在查找元素時自動等待一段時間直到元素出現，如果在指定時間內未找到元素，則拋出異常。

顯式等待(Explicit Wait)

from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.support import expected_conditions as EC# 等待元素可見
element = WebDriverWait(driver, 10).until(EC.visibility_of_element_located((By.ID, "element_id"))
)# 等待元素可點擊
element = WebDriverWait(driver, 10).until(EC.element_to_be_clickable((By.ID, "button_id"))
)# 等待頁面標題包含特定文本
WebDriverWait(driver, 10).until(EC.title_contains("Home Page")
)# 等待元素消失
WebDriverWait(driver, 10).until(EC.invisibility_of_element_located((By.CLASS_NAME, "loading"))
)# 等待警告框出現
WebDriverWait(driver, 10).until(EC.alert_is_present()
)# 等待元素的文本內容滿足條件
WebDriverWait(driver, 10).until(EC.text_to_be_present_in_element((By.ID, "status"), "Success")
)# 等待元素的屬性值滿足條件
WebDriverWait(driver, 10).until(EC.text_to_be_present_in_element_attribute((By.ID, "input"), "value", "text")
)

自定義等待條件

from selenium.webdriver.support.ui import WebDriverWait# 自定義等待條件
def element_has_class(element, class_name):return class_name in element.get_attribute("class").split()# 使用自定義等待條件
element = driver.find_element(By.ID, "myElement")
WebDriverWait(driver, 10).until(lambda driver: element_has_class(element, "active"))

流暢等待(FluentWait)

from selenium.webdriver.support.ui import WebDriverWait
from selenium.common.exceptions import NoSuchElementException, StaleElementReferenceException# 創建FluentWait實例
wait = WebDriverWait(driver,timeout=30,poll_frequency=2,  # 每2秒檢查一次ignored_exceptions=[NoSuchElementException, StaleElementReferenceException]
)# 使用FluentWait
element = wait.until(EC.element_to_be_clickable((By.ID, "myElement")))

2. 異常處理

Selenium操作可能會觸發各種異常，合理的異常處理可以提高腳本的健壯性。

常見異常類型

from selenium.common.exceptions import (NoSuchElementException,  # 元素未找到TimeoutException,        # 等待超時ElementNotVisibleException,  # 元素不可見ElementNotInteractableException,  # 元素不可交互StaleElementReferenceException,  # 元素已過時(DOM已更新)WebDriverException,      # WebDriver通用異常InvalidSelectorException,  # 無效的選擇器UnexpectedAlertPresentException,  # 意外的警告框NoAlertPresentException,  # 沒有警告框SessionNotCreatedException,  # 會話創建失敗ElementClickInterceptedException  # 元素點擊被攔截
)

基本異常處理

try:element = driver.find_element(By.ID, "non_existent_element")element.click()
except NoSuchElementException:print("元素未找到")
except ElementNotInteractableException:print("元素不可交互")
except Exception as e:print(f"發生其他異常: {e}")

重試機制

def retry_click(driver, by, value, max_attempts=3, wait_time=1):"""嘗試多次點擊元素"""from time import sleepfor attempt in range(max_attempts):try:element = driver.find_element(by, value)element.click()return Trueexcept (NoSuchElementException, ElementNotInteractableException, ElementClickInterceptedException, StaleElementReferenceException) as e:if attempt == max_attempts - 1:print(f"無法點擊元素，錯誤: {e}")return Falsesleep(wait_time)return False

處理StaleElementReferenceException

def get_fresh_element(driver, by, value):"""獲取一個新鮮的元素引用，避免StaleElementReferenceException"""try:return driver.find_element(by, value)except StaleElementReferenceException:# 重新查找元素return driver.find_element(by, value)

使用裝飾器處理異常

import functools
from time import sleepdef retry(max_attempts=3, wait_time=1):"""函數重試裝飾器"""def decorator(func):@functools.wraps(func)def wrapper(*args, **kwargs):for attempt in range(max_attempts):try:return func(*args, **kwargs)except (NoSuchElementException, ElementNotInteractableException, StaleElementReferenceException) as e:if attempt == max_attempts - 1:raise esleep(wait_time)return wrapperreturn decorator# 使用裝飾器
@retry(max_attempts=5, wait_time=2)
def click_element(driver, by, value):driver.find_element(by, value).click()

3. 等待策略最佳實踐

1. 避免使用time.sleep()：不靈活且低效
2. 優先使用顯式等待：更精確，可控性更強
3. 結合使用隱式等待和顯式等待：隱式等待作為全局保護，顯式等待針對特定場景
4. 設置合理的超時時間：不要過長或過短
5. 捕獲并處理超時異常：提供適當的恢復機制或用戶友好的錯誤信息
6. 為不同網絡環境調整等待策略：可配置的超時參數

---

面向對象封裝與框架設計

1. 頁面對象模型(Page Object Model, POM)

頁面對象模型是一種設計模式，將頁面的元素和操作封裝在類中，使測試代碼更加清晰和可維護。

基本POM結構

class BasePage:"""所有頁面的基類"""def __init__(self, driver):self.driver = driverdef find_element(self, locator):return self.driver.find_element(*locator)def find_elements(self, locator):return self.driver.find_elements(*locator)def click(self, locator):self.find_element(locator).click()def input_text(self, locator, text):element = self.find_element(locator)element.clear()element.send_keys(text)def get_text(self, locator):return self.find_element(locator).textdef is_element_present(self, locator):try:self.find_element(locator)return Trueexcept NoSuchElementException:return Falsedef wait_for_element(self, locator, timeout=10):try:WebDriverWait(self.driver, timeout).until(EC.presence_of_element_located(locator))return Trueexcept TimeoutException:return Falseclass LoginPage(BasePage):"""登錄頁面對象"""# 頁面元素定位器_username_field = (By.ID, "username")_password_field = (By.ID, "password")_login_button = (By.ID, "login_button")_error_message = (By.CLASS_NAME, "error-message")def __init__(self, driver):super().__init__(driver)self.driver.get("https://example.com/login")def enter_username(self, username):self.input_text(self._username_field, username)return selfdef enter_password(self, password):self.input_text(self._password_field, password)return selfdef click_login(self):self.click(self._login_button)# 根據登錄結果返回不同的頁面對象if "dashboard" in self.driver.current_url:return DashboardPage(self.driver)return selfdef login(self, username, password):self.enter_username(username)self.enter_password(password)return self.click_login()def get_error_message(self):if self.is_element_present(self._error_message):return self.get_text(self._error_message)return ""class DashboardPage(BasePage):"""儀表盤頁面對象"""_welcome_message = (By.ID, "welcome")_logout_button = (By.ID, "logout")def is_loaded(self):return self.wait_for_element(self._welcome_message)def get_welcome_message(self):return self.get_text(self._welcome_message)def logout(self):self.click(self._logout_button)return LoginPage(self.driver)

使用POM進行測試

def test_login_success():driver = webdriver.Chrome()try:login_page = LoginPage(driver)dashboard_page = login_page.login("valid_user", "valid_password")assert dashboard_page.is_loaded()assert "Welcome" in dashboard_page.get_welcome_message()finally:driver.quit()def test_login_failure():driver = webdriver.Chrome()try:login_page = LoginPage(driver)result_page = login_page.login("invalid_user", "invalid_password")assert isinstance(result_page, LoginPage)assert "Invalid credentials" in result_page.get_error_message()finally:driver.quit()

2. 測試框架集成

與unittest集成

import unittest
from selenium import webdriver
from selenium.webdriver.chrome.service import Service
from webdriver_manager.chrome import ChromeDriverManagerclass TestLogin(unittest.TestCase):def setUp(self):self.driver = webdriver.Chrome(service=Service(ChromeDriverManager().install()))self.driver.maximize_window()self.login_page = LoginPage(self.driver)def tearDown(self):self.driver.quit()def test_valid_login(self):dashboard_page = self.login_page.login("valid_user", "valid_password")self.assertTrue(dashboard_page.is_loaded())self.assertIn("Welcome", dashboard_page.get_welcome_message())def test_invalid_login(self):result_page = self.login_page.login("invalid_user", "invalid_password")self.assertIsInstance(result_page, LoginPage)self.assertIn("Invalid credentials", result_page.get_error_message())if __name__ == "__main__":unittest.main()

與pytest集成

import pytest
from selenium import webdriver
from selenium.webdriver.chrome.service import Service
from webdriver_manager.chrome import ChromeDriverManager@pytest.fixture
def driver():# 設置driver = webdriver.Chrome(service=Service(ChromeDriverManager().install()))driver.maximize_window()yield driver# 清理driver.quit()@pytest.fixture
def login_page(driver):return LoginPage(driver)def test_valid_login(login_page):dashboard_page = login_page.login("valid_user", "valid_password")assert dashboard_page.is_loaded()assert "Welcome" in dashboard_page.get_welcome_message()def test_invalid_login(login_page):result_page = login_page.login("invalid_user", "invalid_password")assert isinstance(result_page, LoginPage)assert "Invalid credentials" in result_page.get_error_message()

與Behave(BDD)集成

# features/login.feature
Feature: User LoginAs a userI want to be able to login to the applicationSo that I can access my accountScenario: Successful login with valid credentialsGiven the user is on the login pageWhen the user enters "valid_user" as usernameAnd the user enters "valid_password" as passwordAnd the user clicks the login buttonThen the user should be redirected to the dashboardAnd the dashboard should display a welcome messageScenario: Failed login with invalid credentialsGiven the user is on the login pageWhen the user enters "invalid_user" as usernameAnd the user enters "invalid_password" as passwordAnd the user clicks the login buttonThen the user should remain on the login pageAnd an error message should be displayed

# steps/login_steps.py
from behave import given, when, then
from pages.login_page import LoginPage
from pages.dashboard_page import DashboardPage@given('the user is on the login page')
def step_impl(context):context.login_page = LoginPage(context.driver)@when('the user enters "{username}" as username')
def step_impl(context, username):context.login_page.enter_username(username)@when('the user enters "{password}" as password')
def step_impl(context, password):context.login_page.enter_password(password)@when('the user clicks the login button')
def step_impl(context):context.result_page = context.login_page.click_login()@then('the user should be redirected to the dashboard')
def step_impl(context):assert isinstance(context.result_page, DashboardPage)@then('the dashboard should display a welcome message')
def step_impl(context):assert "Welcome" in context.result_page.get_welcome_message()@then('the user should remain on the login page')
def step_impl(context):assert isinstance(context.result_page, LoginPage)@then('an error message should be displayed')
def step_impl(context):assert "Invalid credentials" in context.result_page.get_error_message()

3. 高級框架設計模式

工廠模式

class PageFactory:"""頁面對象工廠類"""@staticmethoddef get_page(page_name, driver):pages = {"login": LoginPage,"dashboard": DashboardPage,"profile": ProfilePage,"settings": SettingsPage}if page_name.lower() not in pages:raise ValueError(f"不支持的頁面: {page_name}")return pages[page_name.lower()](driver)

單例模式(驅動管理器)

class WebDriverManager:"""WebDriver管理器(單例模式)"""_instance = Nonedef __new__(cls):if cls._instance is None:cls._instance = super(WebDriverManager, cls).__new__(cls)cls._instance.driver = Nonereturn cls._instancedef get_driver(self, browser="chrome"):if self.driver is None:if browser.lower() == "chrome":self.driver = webdriver.Chrome()elif browser.lower() == "firefox":self.driver = webdriver.Firefox()else:raise ValueError(f"不支持的瀏覽器: {browser}")self.driver.maximize_window()self.driver.implicitly_wait(10)return self.driverdef quit(self):if self.driver:self.driver.quit()self.driver = None

策略模式(等待策略)

from abc import ABC, abstractmethodclass WaitStrategy(ABC):"""等待策略基類"""@abstractmethoddef wait_for(self, driver, locator):passclass VisibilityStrategy(WaitStrategy):"""等待元素可見策略"""def wait_for(self, driver, locator, timeout=10):return WebDriverWait(driver, timeout).until(EC.visibility_of_element_located(locator))class ClickableStrategy(WaitStrategy):"""等待元素可點擊策略"""def wait_for(self, driver, locator, timeout=10):return WebDriverWait(driver, timeout).until(EC.element_to_be_clickable(locator))class PresenceStrategy(WaitStrategy):"""等待元素存在策略"""def wait_for(self, driver, locator, timeout=10):return WebDriverWait(driver, timeout).until(EC.presence_of_element_located(locator))# 使用策略模式的高級頁面基類
class AdvancedBasePage:def __init__(self, driver):self.driver = driverself.wait_strategies = {"visible": VisibilityStrategy(),"clickable": ClickableStrategy(),"present": PresenceStrategy()}def find_element(self, locator, strategy="present"):return self.wait_strategies[strategy].wait_for(self.driver, locator)

4. 配置與日志管理

配置管理

import json
import osclass ConfigManager:"""配置管理器"""_instance = Nonedef __new__(cls):if cls._instance is None:cls._instance = super(ConfigManager, cls).__new__(cls)cls._instance.config = {}cls._instance.load_config()return cls._instancedef load_config(self, config_file="config.json"):if os.path.exists(config_file):with open(config_file, "r") as f:self.config = json.load(f)else:# 默認配置self.config = {"browser": "chrome","implicit_wait": 10,"explicit_wait": 20,"base_url": "https://example.com","headless": False,"screenshots_dir": "screenshots","logs_dir": "logs"}def get(self, key, default=None):return self.config.get(key, default)

日志管理

import logging
import os
from datetime import datetimeclass LogManager:"""日志管理器"""_instance = Nonedef __new__(cls):if cls._instance is None:cls._instance = super(LogManager, cls).__new__(cls)cls._instance.setup_logger()return cls._instancedef setup_logger(self):config = ConfigManager().get("logs", {})logs_dir = config.get("dir", "logs")log_level = config.get("level", "INFO")if not os.path.exists(logs_dir):os.makedirs(logs_dir)log_file = os.path.join(logs_dir, f"test_{datetime.now().strftime('%Y%m%d_%H%M%S')}.log")# 設置日志級別映射level_map = {"DEBUG": logging.DEBUG,"INFO": logging.INFO,"WARNING": logging.WARNING,"ERROR": logging.ERROR,"CRITICAL": logging.CRITICAL}# 設置根日志記錄器self.logger = logging.getLogger("selenium_framework")self.logger.setLevel(level_map.get(log_level.upper(), logging.INFO))# 文件處理器file_handler = logging.FileHandler(log_file)file_handler.setLevel(level_map.get(log_level.upper(), logging.INFO))# 控制臺處理器console_handler = logging.StreamHandler()console_handler.setLevel(level_map.get(log_level.upper(), logging.INFO))# 日志格式formatter = logging.Formatter('%(asctime)s - %(name)s - %(levelname)s - %(message)s')file_handler.setFormatter(formatter)console_handler.setFormatter(formatter)# 添加處理器self.logger.addHandler(file_handler)self.logger.addHandler(console_handler)def get_logger(self):return self.logger

---

進階技巧與最佳實踐

1. 高級交互操作

ActionChains高級操作

from selenium.webdriver.common.action_chains import ActionChains
from selenium.webdriver.common.keys import Keys# 基本鼠標操作
def perform_hover(driver, element):"""執行懸停操作"""ActionChains(driver).move_to_element(element).perform()def perform_right_click(driver, element):"""執行右鍵點擊操作"""ActionChains(driver).context_click(element).perform()def perform_double_click(driver, element):"""執行雙擊操作"""ActionChains(driver).double_click(element).perform()def perform_drag_and_drop(driver, source_element, target_element):"""執行拖放操作"""ActionChains(driver).drag_and_drop(source_element, target_element).perform()def perform_drag_and_drop_by_offset(driver, element, x_offset, y_offset):"""執行偏移拖放操作"""ActionChains(driver).drag_and_drop_by_offset(element, x_offset, y_offset).perform()# 組合鍵盤操作
def perform_ctrl_click(driver, element):"""執行Ctrl+點擊操作(多選)"""ActionChains(driver).key_down(Keys.CONTROL).click(element).key_up(Keys.CONTROL).perform()def perform_shift_click(driver, element):"""執行Shift+點擊操作(范圍選擇)"""ActionChains(driver).key_down(Keys.SHIFT).click(element).key_up(Keys.SHIFT).perform()def perform_select_all(driver):"""執行全選操作(Ctrl+A)"""ActionChains(driver).key_down(Keys.CONTROL).send_keys('a').key_up(Keys.CONTROL).perform()def perform_copy(driver):"""執行復制操作(Ctrl+C)"""ActionChains(driver).key_down(Keys.CONTROL).send_keys('c').key_up(Keys.CONTROL).perform()def perform_paste(driver):"""執行粘貼操作(Ctrl+V)"""ActionChains(driver).key_down(Keys.CONTROL).send_keys('v').key_up(Keys.CONTROL).perform()# 鏈式組合操作
def perform_complex_action(driver, element1, element2):"""執行復雜組合操作"""ActionChains(driver)\.move_to_element(element1)\.pause(1)  # 暫停1秒.click()\.move_to_element(element2)\.click()\.perform()

處理JavaScript事件

def trigger_js_event(driver, element, event_name):"""觸發JavaScript事件"""js_code = f"arguments[0].dispatchEvent(new Event('{event_name}'));"driver.execute_script(js_code, element)def focus_element(driver, element):"""使元素獲取焦點"""driver.execute_script("arguments[0].focus();", element)def blur_element(driver, element):"""使元素失去焦點"""driver.execute_script("arguments[0].blur();", element)def scroll_to_element(driver, element):"""滾動到元素位置"""driver.execute_script("arguments[0].scrollIntoView({behavior: 'smooth', block: 'center'});", element)def scroll_to_top(driver):"""滾動到頁面頂部"""driver.execute_script("window.scrollTo(0, 0);")def scroll_to_bottom(driver):"""滾動到頁面底部"""driver.execute_script("window.scrollTo(0, document.body.scrollHeight);")

2. 窗口與標簽頁管理

def switch_to_window_by_title(driver, title):"""切換到指定標題的窗口"""current_window = driver.current_window_handlefor window in driver.window_handles:driver.switch_to.window(window)if title in driver.title:return True# 如果沒有找到匹配標題的窗口，切回原窗口driver.switch_to.window(current_window)return Falsedef switch_to_window_by_url(driver, url_part):"""切換到URL包含指定部分的窗口"""current_window = driver.current_window_handlefor window in driver.window_handles:driver.switch_to.window(window)if url_part in driver.current_url:return True# 如果沒有找到匹配URL的窗口，切回原窗口driver.switch_to.window(current_window)return Falsedef close_all_windows_except_current(driver):"""關閉除當前窗口外的所有窗口"""current_window = driver.current_window_handlefor window in driver.window_handles:if window != current_window:driver.switch_to.window(window)driver.close()driver.switch_to.window(current_window)def open_new_tab(driver, url=None):"""打開新標簽頁"""driver.execute_script("window.open();")driver.switch_to.window(driver.window_handles[-1])if url:driver.get(url)def handle_popup_window(driver, action="accept"):"""處理彈出窗口"""try:if action.lower() == "accept":driver.switch_to.alert.accept()elif action.lower() == "dismiss":driver.switch_to.alert.dismiss()elif action.lower() == "text":return driver.switch_to.alert.textelse:raise ValueError(f"不支持的操作: {action}")return Trueexcept:return False

3. iframe處理

def switch_to_frame_by_index(driver, index):"""通過索引切換到iframe"""try:driver.switch_to.frame(index)return Trueexcept:return Falsedef switch_to_frame_by_name_or_id(driver, name_or_id):"""通過名稱或ID切換到iframe"""try:driver.switch_to.frame(name_or_id)return Trueexcept:return Falsedef switch_to_frame_by_element(driver, element):"""通過元素切換到iframe"""try:driver.switch_to.frame(element)return Trueexcept:return Falsedef switch_to_parent_frame(driver):"""切換到父iframe"""try:driver.switch_to.parent_frame()return Trueexcept:return Falsedef switch_to_default_content(driver):"""切換到主文檔"""try:driver.switch_to.default_content()return Trueexcept:return Falsedef get_iframe_count(driver):"""獲取頁面中iframe的數量"""return len(driver.find_elements(By.TAG_NAME, "iframe"))def execute_in_iframe(driver, iframe_locator, action_func):"""在iframe中執行操作"""driver.switch_to.frame(driver.find_element(*iframe_locator))try:result = action_func(driver)return resultfinally:driver.switch_to.default_content()

4. 文件上傳與下載

文件上傳

def upload_file(driver, file_input_locator, file_path):"""上傳文件(適用于<input type="file">元素)"""try:file_input = driver.find_element(*file_input_locator)file_input.send_keys(file_path)return Trueexcept Exception as e:print(f"文件上傳失敗: {e}")return Falsedef upload_file_without_input(driver, upload_button_locator, file_path):"""上傳文件(適用于沒有可見<input type="file">的情況)使用JS創建一個隱藏的文件輸入元素"""try:# 創建一個隱藏的文件輸入元素js_script = """const input = document.createElement('input');input.type = 'file';input.style.display = 'none';input.id = 'hidden-file-input';document.body.appendChild(input);return input;"""file_input = driver.execute_script(js_script)# 設置文件路徑file_input.send_keys(file_path)# 觸發上傳按鈕的點擊事件upload_button = driver.find_element(*upload_button_locator)driver.execute_script("arguments[0].click();", upload_button)# 移除隱藏的文件輸入元素driver.execute_script("document.getElementById('hidden-file-input').remove();")return Trueexcept Exception as e:print(f"文件上傳失敗: {e}")return False

文件下載

import os
import time
from pathlib import Pathdef setup_chrome_download_path(download_dir):"""設置Chrome瀏覽器的下載路徑"""options = webdriver.ChromeOptions()prefs = {"download.default_directory": download_dir,"download.prompt_for_download": False,"download.directory_upgrade": True,"safebrowsing.enabled": True}options.add_experimental_option("prefs", prefs)return optionsdef wait_for_download_to_complete(download_dir, timeout=60, check_interval=1):"""等待下載完成"""start_time = time.time()while time.time() - start_time < timeout:# 檢查是否有部分下載的文件(.crdownload, .part等)downloading_files = list(Path(download_dir).glob("*.crdownload")) + list(Path(download_dir).glob("*.part"))if not downloading_files:# 找出最近下載的文件downloaded_files = list(Path(download_dir).glob("*"))if downloaded_files:downloaded_files.sort(key=lambda x: x.stat().st_mtime, reverse=True)return str(downloaded_files[0])time.sleep(check_interval)raise TimeoutError("文件下載超時")def download_file(driver, download_button_locator, download_dir, timeout=60):"""下載文件"""try:# 確保下載目錄存在os.makedirs(download_dir, exist_ok=True)# 點擊下載按鈕download_button = driver.find_element(*download_button_locator)download_button.click()# 等待下載完成downloaded_file = wait_for_download_to_complete(download_dir, timeout)return downloaded_fileexcept Exception as e:print(f"文件下載失敗: {e}")return None

5. 截圖與日志

import os
import time
from datetime import datetimedef take_screenshot(driver, directory="screenshots", filename=None):"""截取屏幕截圖"""try:# 確保目錄存在os.makedirs(directory, exist_ok=True)# 如果未指定文件名，使用時間戳生成if not filename:timestamp = datetime.now().strftime("%Y%m%d_%H%M%S")filename = f"screenshot_{timestamp}.png"# 拼接完整路徑file_path = os.path.join(directory, filename)# 截圖driver.save_screenshot(file_path)return file_pathexcept Exception as e:print(f"截圖失敗: {e}")return Nonedef take_element_screenshot(driver, element, directory="screenshots", filename=None):"""截取元素截圖"""try:# 確保目錄存在os.makedirs(directory, exist_ok=True)# 如果未指定文件名，使用時間戳生成if not filename:timestamp = datetime.now().strftime("%Y%m%d_%H%M%S")filename = f"element_screenshot_{timestamp}.png"# 拼接完整路徑file_path = os.path.join(directory, filename)# 截取元素截圖element.screenshot(file_path)return file_pathexcept Exception as e:print(f"元素截圖失敗: {e}")return Nonedef screenshot_on_failure(func):"""失敗時自動截圖的裝飾器"""def wrapper(*args, **kwargs):try:return func(*args, **kwargs)except Exception as e:# 假設第一個參數是self，第二個參數是driverdriver = args[1] if len(args) > 1 else Noneif driver:timestamp = datetime.now().strftime("%Y%m%d_%H%M%S")filename = f"failure_{func.__name__}_{timestamp}.png"take_screenshot(driver, filename=filename)raise ereturn wrapper

6. 高級斷言與驗證

def verify_element_text(driver, locator, expected_text, contains=False):"""驗證元素文本"""try:element = driver.find_element(*locator)actual_text = element.textif contains:assert expected_text in actual_text, f"期望文本包含'{expected_text}'，實際文本為'{actual_text}'"else:assert actual_text == expected_text, f"期望文本為'{expected_text}'，實際文本為'{actual_text}'"return Trueexcept AssertionError as e:print(f"驗證失敗: {e}")return Falsedef verify_element_attribute(driver, locator, attribute, expected_value, contains=False):"""驗證元素屬性"""try:element = driver.find_element(*locator)actual_value = element.get_attribute(attribute)if contains:assert expected_value in actual_value, f"期望屬性'{attribute}'包含'{expected_value}'，實際值為'{actual_value}'"else:assert actual_value == expected_value, f"期望屬性'{attribute}'為'{expected_value}'，實際值為'{actual_value}'"return Trueexcept AssertionError as e:print(f"驗證失敗: {e}")return Falsedef verify_element_visible(driver, locator, timeout=10):"""驗證元素可見"""try:WebDriverWait(driver, timeout).until(EC.visibility_of_element_located(locator))return Trueexcept TimeoutException:print(f"元素在{timeout}秒內未可見: {locator}")return Falsedef verify_element_not_visible(driver, locator, timeout=10):"""驗證元素不可見"""try:WebDriverWait(driver, timeout).until(EC.invisibility_of_element_located(locator))return Trueexcept TimeoutException:print(f"元素在{timeout}秒內仍然可見: {locator}")return Falsedef verify_url(driver, expected_url, contains=False, timeout=10):"""驗證URL"""try:if contains:WebDriverWait(driver, timeout).until(lambda d: expected_url in d.current_url)else:WebDriverWait(driver, timeout).until(lambda d: d.current_url == expected_url)return Trueexcept TimeoutException:print(f"URL驗證失敗，期望URL{'' if contains else '為'}{expected_url}，實際URL為{driver.current_url}")return Falsedef verify_title(driver, expected_title, contains=False, timeout=10):"""驗證頁面標題"""try:if contains:WebDriverWait(driver, timeout).until(lambda d: expected_title in d.title)else:WebDriverWait(driver, timeout).until(lambda d: d.title == expected_title)return Trueexcept TimeoutException:print(f"標題驗證失敗，期望標題{'' if contains else '為'}{expected_title}，實際標題為{driver.title}")return False

---

性能優化與調試技巧

1. 性能測試與優化

測量頁面加載時間

def measure_page_load_time(driver, url):"""測量頁面加載時間"""start_time = time.time()driver.get(url)# 等待頁面完全加載WebDriverWait(driver, 60).until(lambda d: d.execute_script("return document.readyState") == "complete")end_time = time.time()load_time = end_time - start_timereturn load_time

使用Performance API獲取詳細性能數據

def get_performance_metrics(driver):"""獲取瀏覽器性能指標"""# 使用Navigation Timing APInavigation_timing = driver.execute_script("""var performance = window.performance;var timingObj = performance.timing;var loadTime = timingObj.loadEventEnd - timingObj.navigationStart;var dnsTime = timingObj.domainLookupEnd - timingObj.domainLookupStart;var tcpTime = timingObj.connectEnd - timingObj.connectStart;var serverTime = timingObj.responseEnd - timingObj.requestStart;var domTime = timingObj.domComplete - timingObj.domLoading;return {'loadTime': loadTime,'dnsTime': dnsTime,'tcpTime': tcpTime,'serverTime': serverTime,'domTime': domTime,'firstPaint': timingObj.responseStart - timingObj.navigationStart,'ttfb': timingObj.responseStart - timingObj.requestStart};""")return navigation_timingdef get_resource_timing(driver):"""獲取資源加載時間"""resources = driver.execute_script("""var resources = window.performance.getEntriesByType('resource');return resources.map(function(resource) {return {'name': resource.name,'startTime': resource.startTime,'duration': resource.duration,'initiatorType': resource.initiatorType,'size': resource.transferSize};});""")return resources

優化執行速度

def optimize_chrome_for_performance():"""優化Chrome瀏覽器以提高性能"""options = webdriver.ChromeOptions()# 禁用不必要的瀏覽器功能options.add_argument("--disable-extensions")options.add_argument("--disable-gpu")options.add_argument("--disable-dev-shm-usage")options.add_argument("--disable-browser-side-navigation")options.add_argument("--disable-infobars")options.add_argument("--disable-notifications")options.add_argument("--disable-popup-blocking")# 減少內存使用options.add_argument("--disable-features=site-per-process")options.add_argument("--process-per-site")# 禁用圖片加載以提高速度prefs = {"profile.managed_default_content_settings.images": 2,"profile.default_content_setting_values.notifications": 2,"profile.default_content_setting_values.geolocation": 2}options.add_experimental_option("prefs", prefs)# 使用無頭模式options.add_argument("--headless")return options

2. 高級調試技巧

獲取瀏覽器控制臺日志

def get_browser_logs(driver):"""獲取瀏覽器控制臺日志"""logs = driver.get_log('browser')return logsdef print_browser_logs(driver):"""打印瀏覽器控制臺日志"""logs = driver.get_log('browser')for log in logs:print(f"[{log['level']}] {log['message']}")