python - 使用 selenium ide 和 python 在 xpath 进行两次循环迭代后，我的程序失败

Question

两次迭代后失败并显示错误。

如果发生这种情况是因为 selenium ide 找不到 xpath 那么为什么它在循环的第二次迭代时不会失败。

如何在没有任何错误的情况下获得输出，并一一命中所有 8 个 URL，无论 xpath 是否可用。

这是我的代码:

from selenium import webdriver
from selenium.webdriver.common.keys import Keys

#base Url
baseurl="http://www.incredibleindia.org"
driver = webdriver.Firefox()
driver.implicitly_wait(2)
driver.get(baseurl)

driver.implicitly_wait(2)
main_links_tabs=driver.find_elements_by_xpath("html/body/div[3]/div/div[1]/div[2]/ul/li/a")
all_tablength=len(main_links_tabs)
print all_tablength
main_link_list=[]
for i in range(all_tablength): 
    driver.implicitly_wait(3) 
    links=main_links_tabs[i].get_attribute('href')
    main_link_list.append(links) 
#all main_tab_link hit one by one  
for i in  main_link_list:
    print i
    driver.implicitly_wait(30) 
    driver.get(i) 

    #travel tabs data
    print "tabl links hit one by one"

    travel_tabs_sublinks=driver.find_elements_by_xpath(".//*[@id='left-inner-content']/div[2]/div/ul/li/a")

    travel_tabs_sublinks_len=len(travel_tabs_sublinks)
    print travel_tabs_sublinks_len

输出:

8
http://www.incredibleindia.org/en/travel
tabl links hit one by one
http://www.incredibleindia.org/en/trade
tabl links hit one by one
http://www.incredibleindia.org/en/#media
tabl links hit one by one
Traceback (most recent call last):
File "incredibleindia.py", line 27, in <module>
travel_tabs_sublinks=driver.find_elements_by_xpath(".//*[@id='left-        inner-content']/div[2]/div/ul/li/a")
File "/usr/local/lib/python2.7/dist-     packages/selenium/webdriver/remote/webdriver.py", line 244, in     find_elements_by_xpath
return self.find_elements(by=By.XPATH, value=xpath)
File "/usr/local/lib/python2.7/dist-  packages/selenium/webdriver/remote/webdriver.py", line 679, in find_elements
{'using': by, 'value': value})['value']
File "/usr/local/lib/python2.7/dist- packages/selenium/webdriver/remote/webdriver.py", line 175, in execute
self.error_handler.check_response(response)
File "/usr/local/lib/python2.7/dist- packages/selenium/webdriver/remote/errorhandler.py", line 166, in check_response
raise exception_class(message, screen, stacktrace)
selenium.common.exceptions.InvalidSelectorException: Message: The  given selector .//*[@id='left-inner-content']/div[2]/div/ul/li/a is either  invalid or does not result in a WebElement. The following error occurred:
InvalidSelectorError: Unable to locate an element with the xpath   expression .//*[@id='left-inner-content']/div[2]/div/ul/li/a because of  the following error:
TypeError: Argument 1 of Document.createNSResolver is not an object.
Stacktrace:
at FirefoxDriver.annotateInvalidSelectorError_ (file:///tmp/tmpDolyM9/extensions/fxdriver@googlecode.com/components/driver-component.js:10245)
at FirefoxDriver.prototype.findElementsInternal_ (file:///tmp/tmpDolyM9/extensions/fxdriver@googlecode.com/components/driver-component.js:10303)
at fxdriver.Timer.prototype.setTimeout/<.notify (file:///tmp/tmpDolyM9/extensions/fxdriver@googlecode.com/components/driver-component.js:603)

Answer 1

首先，您没有使用 implicitly_wait()正确。它不会只是休眠 N 秒，它实际上会立即执行 - 它告诉驱动程序每次搜索元素时需要等待多长时间:

An implicit wait is to tell WebDriver to poll the DOM for a certain amount of time when trying to find an element or elements if they are not immediately available. The default setting is 0. Once set, the implicit wait is set for the life of the WebDriver object instance.

相反，您需要使用Explicit Waits 。这是代码的改进工作版本:

from selenium import webdriver
from selenium.common.exceptions import TimeoutException
from selenium.webdriver.common.by import By
from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.support import expected_conditions as EC


url = "http://www.incredibleindia.org"
driver = webdriver.Firefox()
driver.get(url)

# wait for menu to being loaded
WebDriverWait(driver, 10).until(EC.presence_of_element_located((By.CSS_SELECTOR, "div.menu li > a")))

links = [a.get_attribute('href') for a in driver.find_elements_by_css_selector('div.menu li > a')]
for link in links:
    driver.get(link)

    # wait for menu to being loaded
    try:
        WebDriverWait(driver, 10).until(EC.presence_of_element_located((By.CSS_SELECTOR, "div#left-inner-content li > a")))
    except TimeoutException:
         print driver.title, "No sublinks"

    sublinks = driver.find_elements_by_css_selector("div#left-inner-content li > a")
    print driver.title, [sublink.text for sublink in sublinks]

打印:

Incredible India - Travel [u'Rural Tourism', u'Mountain Trains & Luxury Trains', u'Eco Tourism', u'MICE', u'All Destinations']
Incredible India - Trade No sublinks
...