跳转至

Selenium 笔记

约 1427 个字 163 行代码 预计阅读时间 7 分钟

View Times

介绍 / Introduction

Selenium 是一个用于自动化 Web 应用程序测试的工具。它提供了一系列的 API 来控制浏览器的行为。 Selenium is a tool for automating web application testing. It provides a set of APIs to control the behavior of the browser.

Selenium 4 是 Selenium 的最新版本，带来了许多新特性和改进。以下是一些主要更新： Selenium 4 is the latest version of Selenium, bringing many new features and improvements. Here are some major updates:

Selenium 4 新特性 / New Features in Selenium 4

  1. W3C WebDriver 标准: Selenium 4 完全支持 W3C WebDriver 标准，这使得浏览器驱动程序的兼容性更好。 W3C WebDriver Standard: Selenium 4 fully supports the W3C WebDriver standard, which improves compatibility with browser drivers.

  2. 相对定位器: 新增了相对定位器，可以更方便地定位元素。 Relative Locators: New relative locators make it easier to locate elements.

    Python
    1
2
3
4
5
6
7
8
9
    from selenium.webdriver.common.by import By
from selenium.webdriver.support.relative_locator import locate_with

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

# 使用相对定位器查找元素
# Find elements using relative locators
element = driver.find_element(locate_with(By.TAG_NAME, "label").above(By.ID, "username"))

  3. 改进的 DevTools 支持: Selenium 4 提供了对 Chrome DevTools 协议的更好支持，可以更方便地进行调试和性能分析。 Improved DevTools Support: Selenium 4 provides better support for the Chrome DevTools Protocol, making it easier to debug and analyze performance.

  4. 新命令: Selenium 4 引入了一些新命令，例如 getElementRect 和 executeCdpCommand。 New Commands: Selenium 4 introduces new commands such as getElementRect and executeCdpCommand.

  5. 改进的文档: Selenium 4 的文档更加详细和易于理解。 Improved Documentation: The documentation for Selenium 4 is more detailed and easier to understand.

注意事项 / Considerations

  1. 浏览器驱动兼容性: 确保使用与 Selenium 4 兼容的浏览器驱动程序。 Browser Driver Compatibility: Ensure that you use browser drivers compatible with Selenium 4.

  2. API 变化: 一些 API 在 Selenium 4 中发生了变化，升级时需要注意。 API Changes: Some APIs have changed in Selenium 4, so be aware of these changes when upgrading.

  3. 性能优化: 利用 Selenium 4 的新特性和改进，可以更好地优化测试性能。 Performance Optimization: Utilize the new features and improvements in Selenium 4 to better optimize test performance.

安装 / Installation

要安装 Selenium，可以使用 pip: To install Selenium, you can use pip:

Bash
1
pip install selenium

此外，你还需要下载相应的浏览器驱动程序，并将其路径添加到系统环境变量中。 Additionally, you need to download the corresponding browser driver and add its path to the system environment variables.

快速开始 / Quick Start

以下是一个简单的示例，展示了如何使用 Selenium 打开一个网页并获取其标题。 Here is a simple example showing how to use Selenium to open a webpage and get its title.

Python
 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
from selenium import webdriver

# 创建一个新的 Chrome 浏览器实例
# Create a new instance of the Chrome browser
driver = webdriver.Chrome()

# 访问一个网页
# Navigate to a webpage
driver.get("https://www.example.com")

# 获取网页标题
# Get the title of the webpage
title = driver.title
print(title)

# 关闭浏览器
# Close the browser
driver.quit()

浏览器驱动 / Browser Drivers

Selenium 需要一个浏览器驱动程序来与浏览器进行通信。以下是一些常用的浏览器驱动程序及其下载链接：
Selenium requires a browser driver to communicate with the browser. Here are some commonly used browser drivers and their download links:

下载后，将驱动程序解压到一个目录，并将该目录添加到系统的 PATH 环境变量中。
After downloading, extract the driver to a directory and add that directory to the system PATH environment variable.

常用操作 / Common Operations

查找元素 / Finding Elements

Selenium 提供了多种方法来查找页面上的元素，例如 find_element_by_id、find_element_by_name、find_element_by_xpath 等。 Selenium provides several methods to find elements on a page, such as find_element_by_id, find_element_by_name, find_element_by_xpath, etc.

以下是一些常用的查找元素的方法及其示例，使用百度和哔哩哔哩网站作为示例。 Here are some commonly used methods to find elements and their examples, using Baidu and Bilibili websites as examples.

通过 ID 查找元素 / Find Element by ID

Python
 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
from selenium import webdriver

driver = webdriver.Chrome()
driver.get("https://www.baidu.com")

# 通过 ID 查找搜索框元素
# Find the search box element by ID
search_box = driver.find_element_by_id("kw")
search_box.send_keys("Selenium")

# 关闭浏览器
# Close the browser
driver.quit()

通过名称查找元素 / Find Element by Name

Python
 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
from selenium import webdriver

driver = webdriver.Chrome()
driver.get("https://www.baidu.com")

# 通过名称查找搜索框元素
# Find the search box element by name
search_box = driver.find_element_by_name("wd")
search_box.send_keys("Selenium")

# 关闭浏览器
# Close the browser
driver.quit()

通过 XPath 查找元素 / Find Element by XPath

Python
 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
from selenium import webdriver

driver = webdriver.Chrome()
driver.get("https://www.bilibili.com")

# 通过 XPath 查找搜索框元素
# Find the search box element by XPath
search_box = driver.find_element_by_xpath("//input[@id='search-keyword']")
search_box.send_keys("Selenium")

# 关闭浏览器
# Close the browser
driver.quit()

通过 CSS 选择器查找元素 / Find Element by CSS Selector

Python
 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
from selenium import webdriver

driver = webdriver.Chrome()
driver.get("https://www.bilibili.com")

# 通过 CSS 选择器查找搜索框元素
# Find the search box element by CSS selector
search_box = driver.find_element_by_css_selector("#search-keyword")
search_box.send_keys("Selenium")

# 关闭浏览器
# Close the browser
driver.quit()

交互操作 / Interacting with Elements

可以对找到的元素进行各种操作，例如点击、输入文本等。 You can perform various actions on the found elements, such as clicking, entering text, etc.

Python
1
2
element.click()
element.send_keys("输入的文本")

等待 / Waiting

在自动化测试中，等待是一个重要的部分。Selenium 提供了显式等待和隐式等待两种方式。 Waiting is an important part of automated testing. Selenium provides both explicit and implicit waits.

Python
 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
from selenium.webdriver.common.by import By
from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.support import expected_conditions as EC

# 显式等待
# Explicit wait
element = WebDriverWait(driver, 10).until(
    EC.presence_of_element_located((By.ID, "element_id"))
)

# 隐式等待
# Implicit wait
driver.implicitly_wait(10)

处理弹窗 / Handling Alerts

在自动化测试中，有时需要处理浏览器弹窗。Selenium 提供了处理弹窗的 API。 Sometimes you need to handle browser alerts in automated testing. Selenium provides APIs to handle alerts.

Python
1
2
3
alert = driver.switch_to.alert
alert.accept()  # 接受弹窗
alert.dismiss()  # 关闭弹窗

截图 / Taking Screenshots

Selenium 还提供了截图功能，可以在测试过程中保存页面截图。 Selenium also provides a screenshot feature to save page screenshots during testing.

Python
1
driver.save_screenshot('screenshot.png')

XPath 语法 / XPath Syntax

XPath 是一种用于在 XML 文档中查找节点的语言。Selenium 支持使用 XPath 查找页面元素。 XPath is a language used for finding nodes in an XML document. Selenium supports using XPath to find elements on a page.

基本语法 / Basic Syntax

  • //tagname[@attribute='value']：选取所有具有指定属性和值的元素。
  • //tagname[text()='text']：选取所有具有指定文本的元素。
  • //tagname[contains(@attribute, 'value')]：选取所有属性包含指定值的元素。
  • //tagname[contains(text(), 'text')]：选取所有文本包含指定值的元素。

学习 XPath / Learning XPath

学习 XPath 语法可以帮助你更好地使用 Selenium 查找页面元素。以下是一些学习资源：
Learning XPath syntax can help you better use Selenium to find page elements. Here are some learning resources:

实际使用 / Practical Usage

在实际使用中，XPath 可以帮助你定位复杂的页面元素。以下是一些实际使用的示例： In practical usage, XPath can help you locate complex page elements. Here are some practical examples:

示例 / Examples

Python
 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
from selenium import webdriver

driver = webdriver.Chrome()
driver.get("https://www.bilibili.com")

# 通过 XPath 查找搜索框元素
# Find the search box element by XPath
search_box = driver.find_element_by_xpath("//input[@id='search-keyword']")
search_box.send_keys("Selenium")

# 通过 XPath 查找包含指定文本的元素
# Find the element containing specified text by XPath
element = driver.find_element_by_xpath("//a[contains(text(), '首页')]")
element.click()

# 关闭浏览器
# Close the browser
driver.quit()

进阶示例 / Advanced Examples

表单处理 / Handling Forms

以下示例展示了如何使用 Selenium 填写并提交表单。 The following example shows how to use Selenium to fill out and submit a form.

Python
 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
from selenium import webdriver
from selenium.webdriver.common.by import By

driver = webdriver.Chrome()
driver.get("https://www.example.com/form")

# 查找表单元素并填写
# Find form elements and fill them out
username = driver.find_element(By.NAME, "username")
password = driver.find_element(By.NAME, "password")
username.send_keys("myusername")
password.send_keys("mypassword")

# 提交表单
# Submit the form
submit_button = driver.find_element(By.NAME, "submit")
submit_button.click()

# 关闭浏览器
# Close the browser
driver.quit()

处理多窗口 / Handling Multiple Windows

以下示例展示了如何使用 Selenium 处理多窗口。 The following example shows how to use Selenium to handle multiple windows.

Python
 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
from selenium import webdriver

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

# 打开一个新窗口
# Open a new window
driver.execute_script("window.open('https://www.example2.com');")

# 切换到新窗口
# Switch to the new window
driver.switch_to.window(driver.window_handles[1])

# 在新窗口中执行操作
# Perform actions in the new window
print(driver.title)

# 关闭新窗口并切换回原窗口
# Close the new window and switch back to the original window
driver.close()
driver.switch_to.window(driver.window_handles[0])

# 关闭浏览器
# Close the browser
driver.quit()

结束 / Conclusion

更多详细信息，请参考 Selenium 官方文档. For more detailed information, please refer to the Selenium official documentation.

评论