I need help with selenium

I am new to programming, I have started to learn selenium for python and after I tried to run the basic test case I got hit with the error ModuleNotFoundError: No module named 'unittest’
although unittest is built in. The code is

import unittest
from selenium import webdriver
from selenium.webdriver.common.keys import Keys
class PythonSearch(unittest.TestCase):
def setUp(self):
self.driver = webdriver.Chrome()

def test_search_in_python_org(self):
    driver = self.driver
    driver.get("http://www.python.org")
    self.assertIn("Python", driver.title)
    elem = driver.find_element_by_name("q")
    elem.send_keys("pycon")
    elem.send_keys(Keys.RETURN)
    assert "No results found." not in driver.page_source

def tearDown(self):
    self.driver.close()

if name == “main”:
unittest.main()