webdriver三種等待方法
1.使用WebDriverWait
from selenium import webdriver
from selenium.webdriver.common.by import By
from selenium.webdriver.support.ui import WebDriverWait # available since 2.4.0
from selenium.webdriver.support import expected_conditions as EC # available since 2.26.0
driver = webdriver.Firefox()
driver.get("http://somedomain/url_that_delays_loading")
try:
element = WebDriverWait(driver， 10).until(EC.presence_of_element_located((By.ID， "myDynamicElement")))
finally:
driver.quit()
presence_of_element_located可以替換為
title_is
title_contains
presence_of_element_located
visibility_of_element_located
visibility_of
presence_of_all_elements_located
text_to_be_present_in_element
text_to_be_present_in_element_value
frame_to_be_available_and_switch_to_it
invisibility_of_element_located
element_to_be_clickable - it is Displayed and Enabled.
staleness_of
element_to_be_selected
element_located_to_be_selected
element_selection_state_to_be
element_located_selection_state_to_be
alert_is_present
By.ID中的ID可替換為'CLASS_NAME'， 'CSS_SELECTOR'， 'ID'， 'LINK_TEXT'， 'NAME'， 'PARTIAL_LINK_TEXT'， 'TAG_NAME'， 'XPATH'
2、隱式等待，相當于設置全局的等待，在定位元素時，對所有元素設置超時時間。
隱式等待使得WebDriver在查找一個Element或者Element數組時，每隔一段特定的時間會輪詢一次DOM，如果Element或數組沒有馬上被發現的話。
默認設置是0。
一旦設置，這個隱式等待會在WebDriver對象實例的整個生命周期起作用。
from selenium import webdriver
driver = webdriver.Firefox()
driver.implicitly_wait(10) # seconds
driver.get(http://www.xxx.com)
myDynamicElement = driver.find_element_by_id("ElementID")
3、強制等待
import time
time.sleep(10)
