python-2.7 - driver.context 无法可靠地返回 webview

Question

Appium 服务器：1.7.2 Appium-Python-Client==0.26 ios：11.2

使用以下内容，我希望找到两个视图，原生视图和 web 视图。本机视图总是返回，但 9/10 次它未能返回 webview 上下文。

    contexts = self.driver.contexts
    print "List of contexts " + str(contexts)
    webview = contexts[1]
    appview = contexts[0]
    self.driver.switch_to.context(webview)
    print "Switched to " + str(webview)
    # Click on link in webview
    self.driver.find_element_by_xpath('/html/body/p[2]/a').click()

因为唯一找到了本机上下文，所以它显然会失败并出现以下错误——

test_1_sso (__main__.SmokeTest) ... List of contexts [u'NATIVE_APP']
ERROR

======================================================================
ERROR: test_1_sso (__main__.SmokeTest)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "test_sso_ios.py", line 121, in test_1_sso
    webview = contexts[1]
IndexError: list index out of range