Appium新版本引发的一个问题

Appium新版本引发的一个问题

准备工作

测试代码

from appium import webdriver
des_cap = {'platformName': 'android'}
driver = webdriver.Remote(command_executor='http://127.0.0.1:4723/wd/hub',
                          desired_capabilities=des_cap)

测试环境

• python 3.10，虚拟环境
• pycharm 2018 community
• 测试时间 2023-7-20

场景一: 默认安装 PASS

• 在pycharm中安装appium-python-client，版本不指定，此时是2.11.1

• 对应依赖selenium4.10.0

• 执行示例代码

• 测试通过

• ??? 所以博主你要表达啥

• 继续看下去

场景二:appium-python-client2.6.0+selenium4.10 FAIL

• 你根据指定版本安装appium-python-client为2.6，自动安装selenium4.10

• 执行示例代码

• 测试失败

• 提示如下

  D:\Appium01\venv\Scripts\python.exe D:/Appium01/demo1.py
  Traceback (most recent call last):
    File "D:\Appium01\demo1.py", line 9, in <module>
      driver = webdriver.Remote(command_executor='http://127.0.0.1:4723/wd/hub',
    File "D:\Appium01\venv\lib\site-packages\appium\webdriver\webdriver.py", line 230, in __init__
      super().__init__(
  TypeError: WebDriver.__init__() got an unexpected keyword argument 'desired_capabilities'
  

场景3:appium-python-client2.6.0+selenium4.3.0 PASS

• 你应该是先安装selenium4.3.0
• 然后再安装appium-python-client2.6.0
• 都是指定版本安装
  • 有同学会说，谁会这样安装呢
  • 会的，因为你可能是先学selenium(我课程要求是4.3，最新的版本4.10的改进对我们没有太大意义，但底层确实改变了很多)
• 测试通过

问题说明

TypeError 分析

• 先看报错

  TypeError: WebDriver.__init__() got an unexpected keyword argument 'desired_capabilities'
  

• 主要版本信息:

  • appium-python-client2.6.0
  • selenium4.10

• 报错行

  driver = webdriver.Remote
  

• Remote是个别名

   from .webdriver import WebDriver as Remote
  

• 看WebDriver源码

  class WebDriver(
      webdriver.Remote,
      ActionHelpers,
      Activities,
      Applications,
      Clipboard,
      Context,
      Common,
      DeviceTime,
      Display,
      ExecuteDriver,
      ExecuteMobileCommand,
      Gsm,
      HardwareActions,
      ImagesComparison,
      IME,
      Keyboard,
      Location,
      LogEvent,
      Network,
      Performance,
      Power,
      RemoteFS,
      ScreenRecord,
      Session,
      Settings,
      Sms,
      SystemBars,
  ):
      def __init__(
          self,
          command_executor: str = 'http://127.0.0.1:4444/wd/hub',
          desired_capabilities: Optional[Dict] = None,
          browser_profile: str = None,
          proxy: str = None,
          keep_alive: bool = True,
          direct_connection: bool = True,
          extensions: Optional[List['WebDriver']] = None,
          strict_ssl: bool = True,
          options: Union[AppiumOptions, List[AppiumOptions]] = None,
      ):
  

• __init__中传递了desired_capabilities没有问题

• 继续分析堆栈

  File "D:\Appium01\venv\lib\site-packages\appium\webdriver\webdriver.py", line 230, in __init__
      super().__init__(
  

• 继续看WebDriver此处源码

          super().__init__(
              command_executor=AppiumConnection(command_executor, keep_alive=keep_alive),
              desired_capabilities=desired_capabilities,
              browser_profile=browser_profile,
              proxy=proxy,
              options=options,
          )
  

• 这里也有desired_capabilities，为何报错了呢

• 请看WebDriver的继承webdriver.Remote

  class WebDriver(BaseWebDriver):
      _web_element_cls = WebElement
      _shadowroot_cls = ShadowRoot
  
      def __init__(
          self,
          command_executor="http://127.0.0.1:4444",
          keep_alive=True,
          file_detector=None,
          options: Union[BaseOptions, List[BaseOptions]] = None,
      ) -> None:
  

• 到这里你发现了，这个__init__里面没有desired_capabilities

• 注意webdriver.Remote是隶属于selenium的，你此时的selenium是4.10，升级了，可能导致它remove了一些参数

appium-python-client2.11.1+selenium4.10

• 这是默认组合，要知道selenium也是4.10了，为何没有报错呢？

• 其调用关系简单分析下

• 在Remote的__init__中，也支持desired_capabilities，但有如下信息

          # TODO: Remove the deprecated arg
          desired_capabilities: Optional[Dict] = None,
  
          if desired_capabilities is not None:
              warnings.warn(
                  'desired_capabilities argument is deprecated and will be removed in future versions. '
                  'Use options instead.',
                  DeprecationWarning,
              )
  

  • 后续要移除desired_capabilities
  • 用options替代(模仿selenium)

• 关键的问题是在于，appium-python-client2.11.1中对父类__init__的调用是不携带desired_capabilities的

          super().__init__(
              command_executor=command_executor,
              options=dst_options,
          )
  

• 完整代码片段如下

  class WebDriver(
      webdriver.Remote,
      ActionHelpers,
      Activities,
      Applications,
      Clipboard,
      Context,
      Common,
      DeviceTime,
      Display,
      ExecuteDriver,
      ExecuteMobileCommand,
      Gsm,
      HardwareActions,
      ImagesComparison,
      IME,
      Keyboard,
      Location,
      LogEvent,
      Network,
      Performance,
      Power,
      RemoteFS,
      ScreenRecord,
      Session,
      Settings,
      Sms,
      SystemBars,
  ):
      def __init__(
          self,
          command_executor: Union[str, AppiumConnection] = 'http://127.0.0.1:4444/wd/hub',
          # TODO: Remove the deprecated arg
          desired_capabilities: Optional[Dict] = None,
          # TODO: Remove the deprecated arg
          browser_profile: Union[str, None] = None,
          # TODO: Remove the deprecated arg
          proxy: Union[str, None] = None,
          keep_alive: bool = True,
          direct_connection: bool = True,
          extensions: Optional[List['WebDriver']] = None,
          strict_ssl: bool = True,
          options: Union[AppiumOptions, List[AppiumOptions], None] = None,
      ):
          if strict_ssl is False:
              # pylint: disable=E1101
              # noinspection PyPackageRequirements
              import urllib3
  
              # pylint: disable=E1101
              # noinspection PyPackageRequirements
              import urllib3.exceptions
  
              # noinspection PyUnresolvedReferences
              AppiumConnection.set_certificate_bundle_path(None)
              urllib3.disable_warnings(urllib3.exceptions.InsecureRequestWarning)
  
          if isinstance(command_executor, str):
              command_executor = AppiumConnection(command_executor, keep_alive=keep_alive)
  
          if browser_profile is not None:
              warnings.warn('browser_profile argument is deprecated and has no effect', DeprecationWarning)
  
          if proxy is not None:
              warnings.warn('proxy argument is deprecated and has no effect', DeprecationWarning)
  
          if desired_capabilities is not None:
              warnings.warn(
                  'desired_capabilities argument is deprecated and will be removed in future versions. '
                  'Use options instead.',
                  DeprecationWarning,
              )
          # TODO: Remove the fallback after desired_capabilities removal
          dst_options = (
              AppiumOptions().load_capabilities(desired_capabilities)
              if desired_capabilities is not None and options is None
              else options
          )
  
          super().__init__(
              command_executor=command_executor,
              options=dst_options,
          )
  

appium-python-client2.6.0+selenium4.3.0

• 想必分析到此处，你应该盲猜能知道为何这个也PASS了

• 是因为selenium的版本中webdriver.Remote中是有desired_capabilities的

  class WebDriver(BaseWebDriver):
      _web_element_cls = WebElement
      _shadowroot_cls = ShadowRoot
  
      def __init__(self, command_executor='http://127.0.0.1:4444',
                   desired_capabilities=None, browser_profile=None, proxy=None,
                   keep_alive=True, file_detector=None, options: Union[BaseOptions, List[BaseOptions]] = None):
  

总结

• 最新版本appium-python-client即将不提供desired_capabilities的传参，但目前能用
• 在selenium4.10中已经不支持desired_capabilities参数
• 错误的搭配可能会引发上述问题，要么用最新的版本(默认安装)，要么2个都用较低的版本
• 留在最后的问题，那么在appium最新版中应该如何传递能力值呢?