selenium 2 和 python 3.4.1 的问题

Question

我有一个简单的自动化来填写登录表单字段。实际上，它通过了很好，但是有问题。在脚本填充字段后，我需要在控制台中查看实际输出，例如“登录成功”或“找不到用户名”。我尝试了很多东西，但没有任何效果，我最后一次尝试是 while 循环，效果很好，但只有当我有积极的结果时。我写了第二个条件，但是当我输入不正确的数据时，在我的控制台中看到所有这些错误让我发疯。这是代码和部分输出。

from selenium import webdriver
from selenium.webdriver.common.by import By
from selenium.webdriver.support.ui import Select
from selenium.common.exceptions import NoSuchElementException

baseurl = "http://www.somesite/login"
email = input("Type an email: ")
password = input("Type a password: ")

xpaths = { 'loginBox' : "//input[@id='session_email']",
           'passwordBox' : "//input[@id='session_password']",
           'submitButton' :   "//input[@class='ufs-but']",
           'success' : "//div[@class='flash-message success']",
           'error' : "//span[@class='form_error']"
         }


mydriver = webdriver.Firefox()
mydriver.get(baseurl)


mydriver.find_element_by_xpath(xpaths['loginBox']).send_keys(email)


mydriver.find_element_by_xpath(xpaths['passwordBox']).send_keys(password)


mydriver.find_element_by_xpath(xpaths['submitButton']).click()


while mydriver.find_element_by_xpath(xpaths['success']):
    print("Success")
    if mydriver.find_element_by_xpath(xpaths['error']):
        print("No")

当我尝试中断错误时，我得到了结果：

File "ab.py", line 32, in <module>
    while mydriver.find_element_by_xpath(xpaths['success']):
  File "/usr/local/lib/python3.4/site-packages/selenium-2.43.0-py3.4.egg/selenium/webdriver/remote/webdriver.py", line 230, in find_element_by_xpath
    return self.find_element(by=By.XPATH, value=xpath)
  File "/usr/local/lib/python3.4/site-packages/selenium-2.43.0-py3.4.egg/selenium/webdriver/remote/webdriver.py", line 662, in find_element
    {'using': by, 'value': value})['value']
  File "/usr/local/lib/python3.4/site-packages/selenium-2.43.0-py3.4.egg/selenium/webdriver/remote/webdriver.py", line 173, in execute
    self.error_handler.check_response(response)
  File "/usr/local/lib/python3.4/site-packages/selenium-2.43.0-py3.4.egg/selenium/webdriver/remote/errorhandler.py", line 166, in check_response
    raise exception_class(message, screen, stacktrace)
selenium.common.exceptions.NoSuchElementException: Message: 'Unable to locate element: {"method":"xpath","selector":"//div[@class=\'flash-message success\']"}' ; Stacktrace: 
    at FirefoxDriver.prototype.findElementInternal_ (file:///tmp/tmpjax8kj1u/extensions/fxdriver@googlecode.com/components/driver-component.js:9618:26)
    at FirefoxDriver.prototype.findElement (file:///tmp/tmpjax8kj1u/extensions/fxdriver@googlecode.com/components/driver-component.js:9627:3)
    at DelayedCommand.prototype.executeInternal_/h (file:///tmp/tmpjax8kj1u/extensions/fxdriver@googlecode.com/components/command-processor.js:11612:16)
    at DelayedCommand.prototype.executeInternal_ (file:///tmp/tmpjax8kj1u/extensions/fxdriver@googlecode.com/components/command-processor.js:11617:7)
    at DelayedCommand.prototype.execute/< (file:///tmp/tmpjax8kj1u/extensions/fxdriver@googlecode.com/components/command-processor.js:11559:5) 

正如我所说，成功的结果不是问题。

UPD。我稍微更正了代码的最后一部分，现在我有了这个：

while mydriver.find_element_by_xpath(xpaths['success']):
    print("Success")
    break
while mydriver.find_element_by_xpath(xpaths['error']):
    print("No")
    break

当我想要一个否定结果时，它可以工作，但不像我想要的那样输出：

Type an email: w
Type a password: wer
Success
No

如您所见，我想在结果为正时看到“成功”，在结果为负时看到“否”，但我不想同时看到它们。

UPD。向Macro Giancarli 提供巨大帮助的道具，这就是我得到我想要的东西的方式：

try:
    success = True
    success_element = mydriver.find_element_by_xpath(xpaths['success'])
except NoSuchElementException:
    success = False
    print("Can't log in. Check email and/or password")
try:
    failure = True
    failure_element = mydriver.find_element_by_xpath(xpaths['error'])
except NoSuchElementException :
    failure = False
    print("Logged in successfully")

Answer 1

问题似乎在于您最后构建 while 循环的方式。您不需要循环来检查成功或失败。

假设您输入了登录数据，假设有四种结果。您可以找到决定成功的元素，找到决定失败的元素，找到两者（应该是不可能的），或者都找不到（可能是在意外屏幕的情况下，或者页面加载失败）。

不要期望 webdriver 查询返回一些值，而是尝试将它们放入 try 块中以捕获 NoSuchElementException 并检查非 None 内容。另外，请尝试处理这四种情况，以减少您的程序崩溃的频率。

编辑：

试试这个。

try:
    success = True
    success_element = mydriver.find_element_by_xpath(xpaths['success'])
except NoSuchElementException:
    success = False
try:
    failure = True
    failure_element = mydriver.find_element_by_xpath(xpaths['error'])
except NoSuchElementException :
    failure = False
# now handle the four possibilities