How to understand that a page has an alert or not with use of Selenium in Python?

Question

There are many solutions for interaction with alerts in web pages using Selenium in Python. But, I want a solution to find that the page has an alert or no. Use of Try & except is very bad solution in my case. So, don't present that. I want just a simple if & else solution. This is my solution:

if driver.switch_to_alert()
  alert = driver.switch_to_alert()
  alert.accept()
else:
  print('hello')

NoAlertPresentException: no such alert
  (Session info: chrome=73.0.3683.103)
  (Driver info: chromedriver=2.46.628402 (536cd7adbad73a3783fdc2cab92ab2ba7ec361e1),platform=Windows NT 10.0.16299 x86_64)

https://stackoverflow.com/questions/19003003/check-if-any-alert-exists-using-selenium-with-python And do you mean just window.alert? — QHarr, Apr 14 '19 at 14:26

score 1 · Answer 1 · answered Apr 14 '19 at 19:53

When you automate the Regression Testcases you are always aware that where there is an alert on the webpage. As per the current implementation to switch to an Alert you need to use:

switch_to.alert() as follows:

selenium.webdriver.common.alert 
driver.switch_to.alert().accept()

As per best practices you should always induce WebDriverWait for the alert_is_present() while switching to an Alert as follows:

from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.common.by import By
from selenium.webdriver.support import expected_conditions as EC
# other lines of code
WebDriverWait(driver, 5).until(EC.alert_is_present).accept()

To validate that a page has an Alert or not the ideal approach would be to wrap up the Alert handling code block in a try-catch{} block as follows:

from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.common.by import By
from selenium.webdriver.support import expected_conditions as EC
from selenium.common.exceptions import TimeoutException

try:
    WebDriverWait(driver, 5).until(EC.alert_is_present).accept()
    print("Alert accepted")
except TimeoutException:
    print("No Alert was present")

Reference

You can find a couple of relevant discussion in:

Outro

There may be some cases when you may need to interact with elements those cannot be inspected through css/xpath within google-chrome-devtools and you will find a detailed discussion in How to interact with elements those cannot be inspected through css/xpath within google-chrome-devtools

score 1 · Accepted Answer · answered Apr 14 '19 at 22:40

1

You can do:

driver.executeScript("window.alert = () => window.alertHappened = true")
// some code here that may cause alert
alert_happened = driver.executeScript("return !!window.alertHappened")

answered Apr 14 '19 at 22:40

pguardiario

53,827
19
119
159

How to understand that a page has an alert or not with use of Selenium in Python?

2 Answers2

Reference

Outro