引发TimeoutException(message，screen，stacktrace) TimeoutException:消息：

Question

一般来说，我是python和selenium的新手，我正在尝试我在youtube上看到的一个示例。以下是代码示例：

from selenium import webdriver
from selenium.webdriver.common.keys import Keys
from selenium.webdriver.support.ui import WebDriverWait
import unittest 

class LoginTest(unittest.TestCase):

def test_Login(self):
    self.driver = webdriver.Firefox()
    self.driver.get("https://www.facebook.com/")
    driver = self.driver
    facebookUsername = "xxxxxxxx"
    facebookPassword = "xxxxxxxx"

    emailFieldId="email"
    passFieldId ="pass"
    loginButtonXpath="//input[@value='Log in']"
    fbLogoXpath = "(//a[contains(@href,'logo')])[1]"

    emailFieldElement = WebDriverWait(driver, 1).until(lambda driver: driver.find_element_by_id(emailFieldId))
    passFieldElement = WebDriverWait(driver, 1).until(lambda driver: driver.find_element_by_id(passFieldId))
    loginButtonElement = WebDriverWait(driver, 1).until(lambda driver: driver.find_element_by_id(loginButtonXpath))

    emailFieldElement.clear()
    emailFieldElement.send_keys(facebookUsername)
    passFieldElement.clear()
    passFieldElement.send_keys(facebookPassword)
    loginButtonElement.click()
    WebDriverWait(driver, 1).until(lambda driver:     driver.find_element_by_id(fbLogoXpath))
def tearDown(self):
    self.driver.quit()

if __name__ == "__main__":
unittest.main()

当我运行它输入到facebook的代码时，它停止了，并给我这个错误。

ERROR: test_Login (__main__.LoginTest)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "facebot.py", line 25, in test_Login
    loginButtonElement = WebDriverWait(driver, 1).until(lambda driver: driver.find_element_by_id(loginButtonXpath))
  File "C:\Python27\lib\site-packages\selenium\webdriver\support\wait.py", line 76, in until
    raise TimeoutException(message, screen, stacktrace)
TimeoutException: Message:
Stacktrace:
    at FirefoxDriver.prototype.findElementInternal_ (file:///c:/users/ale/appdata/local/temp/tmpmle1b1/extensions/fxdriv
er@googlecode.com/components/driver-component.js:10667)
    at FirefoxDriver.prototype.findElement (file:///c:/users/ale/appdata/local/temp/tmpmle1b1/extensions/fxdriver@google
code.com/components/driver-component.js:10676)
    at DelayedCommand.prototype.executeInternal_/h (file:///c:/users/ale/appdata/local/temp/tmpmle1b1/extensions/fxdrive
r@googlecode.com/components/command-processor.js:12643)
    at DelayedCommand.prototype.executeInternal_ (file:///c:/users/ale/appdata/local/temp/tmpmle1b1/extensions/fxdriver@
googlecode.com/components/command-processor.js:12648)
    at DelayedCommand.prototype.execute/< (file:///c:/users/ale/appdata/local/temp/tmpmle1b1/extensions/fxdriver@googlec
ode.com/components/command-processor.js:12590)

----------------------------------------------------------------------
Ran 1 test in 16.262s

我试着通过看youtube来修复它，但是我卡住了，不知道它是什么。

Answer 1

对于初学者来说，超时值太小，请增大它。此外，您只能定义WebDriverWait实例一次，然后重用：

wait = WebDriverWait(driver, 10)

emailFieldElement = wait.until(lambda driver: driver.find_element_by_id(emailFieldId))
passFieldElement = wait.until(lambda driver: driver.find_element_by_id(passFieldId))
loginButtonElement = wait.until(lambda driver: driver.find_element_by_xpath(loginButtonXpath))

此外，请注意，在定位“登录”按钮时，您应该使用find_element_by_xpath()而不是find_element_by_id()。