test.py

from selenium import webdriver
from selenium.webdriver.support.select import Select
from selenium.common.exceptions import UnexpectedTagNameException
from selenium.webdriver.common.alert import Alert
import pytest


def test_without_isolation():
    wd = webdriver.Chrome()
    wd.get('https://www.selenium.dev/')
    element = wd.find_element_by_tag_name('div')
    try:
        select = Select(element)
        assert False
    except UnexpectedTagNameException:
        pass


def test_with_isolation(mocker):
    mockElement = mocker.patch('selenium.webdriver.remote.webelement.WebElement')
    element = mockElement.return_value
    element.tag_name = 'div'

    try:
        select = Select(element)
        assert False
    except UnexpectedTagNameException:
        pass