Appium遇到的问题(持续更新....)

C:\Python27\python.exe D:/Demo/temp/appium.py
Traceback (most recent call last):
  File "D:/Demo/temp/appium.py", line 3, in <module>
    from appium import webdriver
  File "D:\Demo\temp\appium.py", line 14, in <module>
    driver = webdriver.Remote(‘http://localhost:4723/wd/hub‘, desired_caps)
  File "C:\Python27\Lib\site-packages\selenium\webdriver\remote\webdriver.py", line 140, in __init__
    self.start_session(desired_capabilities, browser_profile)
  File "C:\Python27\Lib\site-packages\selenium\webdriver\remote\webdriver.py", line 229, in start_session
    response = self.execute(Command.NEW_SESSION, parameters)
  File "C:\Python27\Lib\site-packages\selenium\webdriver\remote\webdriver.py", line 297, in execute
    self.error_handler.check_response(response)
  File "C:\Python27\Lib\site-packages\selenium\webdriver\remote\errorhandler.py", line 194, in check_response
    raise exception_class(message, screen, stacktrace)
selenium.common.exceptions.WebDriverException: Message: A new session could not be created. (Original error: No app set; either start appium with --app or pass in an ‘app‘ value in desired capabilities, or set androidPackage to launch pre-existing app on device)


Process finished with exit code 1