from selenium.webdriver.support import expected_conditions

from selenium.webdriver.support.ui import WebDriverWait

from selenium.webdriver.common.by import By

from selenium import webdriver

driver=webdriver.Chrome()

driver.maximize_window()

driver.get('https://baidu.com')

driver.implicitly_wait(30) 

#元素是否出现可点 ,参数是locator

xinwei=WebDriverWait(driver,5).until(expected_conditions.element_to_be_clickable((By.CSS_SELECTOR,'.mnav')))

xinwei.click()

#验证相应位置元素的文本信息,返回值是布尔  俩参数locator  text

driver.find_element_by_xpath(".//*[@id='u1']/a[7]").click()

driver.find_element_by_id('TANGRAM__PSP_10__userName').send_keys('')

driver.find_element_by_id('TANGRAM__PSP_10__submit').click()

bo=WebDriverWait(driver,5).until(expected_conditions.text_to_be_present_in_element((By.CSS_SELECTOR,'#TANGRAM__PSP_10__error'),'请您输入密码'))

print(bo)#打印结果：True

#元素是否可见，可见后操作  参数是locator

sou=WebDriverWait(driver,5).until(expected_conditions.visibility_of_element_located((By.CSS_SELECTOR,'#kw')))

sou.send_keys('java')

driver.quit()