python - 等到加载器消失 python selenium

Question

<div id="loader-mid" style="position: absolute; top: 118.5px; left: 554px; display: none;">
    <div class="a">Loading</div>
    <div class="b">please wait...</div>
</div>

并想等到它消失。我有以下代码，但有时等待时间太长，在某些代码点突然卡住所有进程，我不知道为什么。

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

self.wait = WebDriverWait(driver, 10)

self.wait.until(EC.invisibility_of_element_located((By.XPATH, "//*[@id='loader_mid'][contains(@style, 'display: block')]")))

我也试过这个:

self.wait.until_not(EC.presence_of_element_located((By.XPATH, "//*[@id='loader_mid'][contains(@style, 'display: block')]")))

我不知 Prop 体如何检查，但也许我的元素总是出现在页面上并且 selenium 认为它在那里，唯一改变的是参数显示从无变为 block 。我想我可以得到像字符串这样的属性并检查是否有单词“block”但是我觉得这是错误的......请帮助我。

Answer 1

重申了您的答案(并进行了一些错误处理)以使人们更容易找到解决方案:)

导入所需的类:

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

配置变量:

SHORT_TIMEOUT  = 5   # give enough time for the loading element to appear
LONG_TIMEOUT = 30  # give enough time for loading to finish
LOADING_ELEMENT_XPATH = '//*[@id="xPath"]/xPath/To/The/Loading/Element'

代码解决方案:

try:
    # wait for loading element to appear
    # - required to prevent prematurely checking if element
    #   has disappeared, before it has had a chance to appear
    WebDriverWait(driver, SHORT_TIMEOUT
        ).until(EC.presence_of_element_located((By.XPATH, LOADING_ELEMENT_XPATH)))

    # then wait for the element to disappear
    WebDriverWait(driver, LONG_TIMEOUT
        ).until_not(EC.presence_of_element_located((By.XPATH, LOADING_ELEMENT_XPATH)))

except TimeoutException:
    # if timeout exception was raised - it may be safe to 
    # assume loading has finished, however this may not 
    # always be the case, use with caution, otherwise handle
    # appropriately.
    pass