selenium关于no len()问题

一直报TypeError: object of type 'WebElement' has no len()
下面是我的代码

from selenium.webdriver.common.action_chains import ActionChains
from selenium.webdriver.chrome.service import Service
from selenium import webdriver
from selenium.webdriver.common.by import By

web = webdriver.Chrome(service=Service('D:/chromedriver_win32/chromedriver.exe'))
web.get('https://www.zhihu.com/signin?next=%2F')
action = ActionChains(web)

password_log = web.find_element(By.XPATH,value='//form/div/div[@role="button"][2]')
password_log.click()


usernameTag = web.find_element(By.NAME, 'username')
action.move_to_element(usernameTag)
action.send_keys(usernameTag,'1479709179')
# action.send_keys(usernameTag,'1479709179')

passwordTag = web.find_element(By.NAME,'password')
action.move_to_element(passwordTag).send_keys('123456')


submit = web.find_element(By.CLASS_NAME,'SignFlow-submitButton')
action.move_to_element(submit)
action.click(submit)
web.quit()

明面上看不到调用了len()方法哇，对象没有len()方法，还没看到调用的地方

把action.send_keys(usernameTag,'1479709179') 改成
action.send_keys_to_element(usernameTag, '1479709179')就不报错了，但是不能把值输入进去