把WebDriverWait放在While循环中并捕获异常如何?

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

browser = webdriver.Firefox()
browser.get("url")
delay = 3 # seconds
while True:
    try:
        WebDriverWait(browser, delay).until(EC.presence_of_element_located(browser.find_element_by_id('IdOfMyElement')))
        print "Page is ready!"
        break # it will break from the loop once the specific element will be present. 
    except TimeoutException:
        print "Loading took too much time!-Try again"

从硒/ webdriver /支持/ wait.py

driver = ...
from selenium.webdriver.support.wait import WebDriverWait
element = WebDriverWait(driver, 10).until(
    lambda x: x.find_element_by_id("someId"))

如果您试图滚动并找到页面上的所有项目。您可以考虑使用以下方法。这是其他人在这里提到的一些方法的组合。它帮我完成了任务:

while True:
    try:
        driver.execute_script("window.scrollTo(0, document.body.scrollHeight);")
        driver.implicitly_wait(30)
        time.sleep(4)
        elem1 = WebDriverWait(driver, 30).until(EC.presence_of_all_elements_located((By.CSS_SELECTOR, "element-name")))
        len_elem_1 = len(elem1)
        print(f"A list Length {len_elem_1}")
        driver.execute_script("window.scrollTo(0, document.body.scrollHeight);")
        driver.implicitly_wait(30)
        time.sleep(4)
        elem2 = WebDriverWait(driver, 30).until(EC.presence_of_all_elements_located((By.CSS_SELECTOR, "element-name")))
        len_elem_2 = len(elem2)
        print(f"B list Length {len_elem_2}")
        if len_elem_1 == len_elem_2:
            print(f"final length = {len_elem_1}")
            break
    except TimeoutException:
            print("Loading took too much time!")

Selenium无法检测页面是否完全加载，但javascript可以。我建议你试试这个。

from selenium.webdriver.support.ui import WebDriverWait
WebDriverWait(driver, 100).until(lambda driver: driver.execute_script('return document.readyState') == 'complete')

这将执行javascript代码，而不是使用python，因为javascript可以检测页面何时完全加载，它将显示“完成”。这个代码的意思是在100秒内，继续尝试这个文档。readyState直到complete显示。

正如David Cullen的回答中提到的，我总是看到这样的建议:

element_present = EC.presence_of_element_located((By.ID, 'element_id'))
WebDriverWait(driver, timeout).until(element_present)

对于我来说，很难找到所有可以与By一起使用的定位器，所以我认为在这里提供列表会很有用。 根据Ryan Mitchell的Web Scraping with Python:

ID Used in the example; finds elements by their HTML id attribute CLASS_NAME Used to find elements by their HTML class attribute. Why is this function CLASS_NAME not simply CLASS? Using the form object.CLASS would create problems for Selenium's Java library, where .class is a reserved method. In order to keep the Selenium syntax consistent between different languages, CLASS_NAME was used instead. CSS_SELECTOR Finds elements by their class, id, or tag name, using the #idName, .className, tagName convention. LINK_TEXT Finds HTML tags by the text they contain. For example, a link that says "Next" can be selected using (By.LINK_TEXT, "Next"). PARTIAL_LINK_TEXT Similar to LINK_TEXT, but matches on a partial string. NAME Finds HTML tags by their name attribute. This is handy for HTML forms. TAG_NAME Finds HTML tags by their tag name. XPATH Uses an XPath expression ... to select matching elements.

在代码中使用:

from selenium import webdriver

driver = webdriver.Firefox() # or Chrome()
driver.implicitly_wait(10) # seconds
driver.get("http://www.......")

或者你可以使用这段代码，如果你正在寻找一个特定的标签:

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

driver = webdriver.Firefox() #or Chrome()
driver.get("http://www.......")
try:
    element = WebDriverWait(driver, 10).until(
        EC.presence_of_element_located((By.ID, "tag_id"))
    )
finally:
    driver.quit()