Unable to login with python selenium error:NoSuchElementException error

问题

I have tried locating the submit button by id and xpath but none of them worked and checked in the page source ,the id is same.I have no idea why this is happening even though I am giving the correct Id or xpath

URL : https://moodle.niituniversity.in/moodle/login/index.php

from pyvirtualdisplay import Display
from selenium import webdriver
from selenium.webdriver.common.keys import Keys
display = Display(visible=0, size=(1024, 768))
display.start()
driver = webdriver.Firefox()
#driver.set_preference("browser.startup.homepage_override.mstone", "ignore")
driver.get("https://moodle.niituniversity.in/moodle/login/index.php")
username = driver.find_element_by_name("username")
username.clear()
username.send_keys("User123")
username.send_keys(Keys.RETURN)
password = driver.find_element_by_name("password")
password.clear()
password.send_keys("pass123")
password.send_keys(Keys.RETURN)
password = driver.find_element_by_xpath(".//*[@id='loginbtn']").click()
driver.get("https://moodle.niituniversity.in/moodle")
assert "user" in driver.page_source
driver.close()
display.stop()

.NoSuchElementException: Message: Unable to locate element: {"method":"xpath","selector":".//*[@id='loginbtn']"}

回答1:

Might be possible this is timing issue, you should implement WebDriverWait to wait until button present on page as below :-

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

element = WebDriverWait(driver, 10).until(
    EC.presence_of_element_located((By.ID, "loginbtn")))
element.click()

Full code :

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.get("https://moodle.niituniversity.in/moodle/login/index.php")
username = driver.find_element_by_name("username")
username.clear()
username.send_keys("User123")

password = driver.find_element_by_name("password")
password.clear()
password.send_keys("pass123")

button = WebDriverWait(driver, 10).until(
    EC.presence_of_element_located((By.ID, "loginbtn")))
button.click()

来源：https://stackoverflow.com/questions/38961190/unable-to-login-with-python-selenium-errornosuchelementexception-error