如何告诉Python等待Selenium？

Question

我可以用下面的代码过滤数据，但导出到Excel不起作用。我请求您的帮助，如何改进我下面的代码片段，以指示Python等待数据完全加载，然后将excel文件下载到所需的文件夹中。在

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

driver = webdriver.Chrome("C:\Python27\Scripts\chromedriver.exe")
driver.get("https://etrakit.friscotexas.gov/Search/permit.aspx")

number_option = driver.find_element_by_id("cplMain_btnSearch")
number_option.click()

delay = 3 
try:
     WebDriverWait(driver, delay).until(EC.presence_of_element_located(driver.find_element_by_id("cplMain_btnSearch")))
    print "Page is ready!"
except TimeoutException:
    print "Loading took too much time!"


search_button = driver.find_element_by_id("cplMain_btnExportToExcel")
search_button.click()

options.add_argument("download.default_directory=C:\Users\Patrick\Desktop\Programming\R Files")
driver = webdriver.Chrome(chrome_options=options)

driver.close()

错误：

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Answer 1

试着换掉这个

 WebDriverWait(driver, delay).until(EC.presence_of_element_located(driver.find_element_by_id("cplMain_btnSearch"))

用这个

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Answer 2

你的问题是：

EC.presence_of_element_located(driver.find_element_by_id("cplMain_btnSearch"))

等待的重点是不要尝试自己寻找元素，因为它可能还不存在！在本例中，您碰巧找到了它，错误是因为您使用了presence_of_element_located。以下是您需要做的：

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参见文档：http://selenium-python.readthedocs.io/waits.html#explicit-waits