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()

webdriver将在默认情况下通过.get()方法等待页面加载。

正如你可能正在寻找一些特定的元素@user227215所说的，你应该使用WebDriverWait来等待位于你页面中的元素:

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

browser = webdriver.Firefox()
browser.get("url")
delay = 3 # seconds
try:
    myElem = WebDriverWait(browser, delay).until(EC.presence_of_element_located((By.ID, 'IdOfMyElement')))
    print "Page is ready!"
except TimeoutException:
    print "Loading took too much time!"

我用它来检查提醒。您可以使用任何其他类型方法来查找定位器。

编辑1:

I should mention that the webdriver will wait for a page to load by default. It does not wait for loading inside frames or for ajax requests. It means when you use .get('url'), your browser will wait until the page is completely loaded and then go to the next command in the code. But when you are posting an ajax request, webdriver does not wait and it's your responsibility to wait an appropriate amount of time for the page or a part of page to load; so there is a module named expected_conditions.

回答得很好。等待XPATH的快速示例。

# wait for sizes to load - 2s timeout
try:
    WebDriverWait(driver, 2).until(expected_conditions.presence_of_element_located(
        (By.XPATH, "//div[@id='stockSizes']//a")))
except TimeoutException:
    pass

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.

找到以下3种方法:

请求处理

检查页面readyState(不可靠):

def page_has_loaded(self):
    self.log.info("Checking if {} page is loaded.".format(self.driver.current_url))
    page_state = self.driver.execute_script('return document.readyState;')
    return page_state == 'complete'

wait_for helper函数很好，但不幸的是，click_through_to_new_page处于竞速条件，在浏览器开始处理单击之前，我们设法在旧页面中执行脚本，而page_has_loaded直接返回true。

id

比较新页面id和旧页面id:

def page_has_loaded_id(self):
    self.log.info("Checking if {} page is loaded.".format(self.driver.current_url))
    try:
        new_page = browser.find_element_by_tag_name('html')
        return new_page.id != old_page.id
    except NoSuchElementException:
        return False

比较id可能不如等待过时的引用异常有效。

staleness_of

使用staleness_of方法:

@contextlib.contextmanager
def wait_for_page_load(self, timeout=10):
    self.log.debug("Waiting for page to load at {}.".format(self.driver.current_url))
    old_page = self.find_element_by_tag_name('html')
    yield
    WebDriverWait(self, timeout).until(staleness_of(old_page))

要了解更多细节，请查看Harry的博客。

nono = driver.current_url
driver.find_element(By.XPATH,"//button[@value='Send']").click()
  while driver.current_url == nono:
      pass
print("page loaded.")