#!/usr/bin/env python 
# -*- coding: utf-8 -*-
from selenium import webdriver
from selenium.webdriver.common.keys import Keys
import time
driver = webdriver.Firefox()
driver.get('https://www.youtube.com/')
assert 'YouTube' in driver.title
elem = driver.find_element_by_name('search_query')
elem.send_keys("Самые красивые места на планете" + Keys.ENTER)
time.sleep(5)
print(driver.current_url)

>>> from urllib.parse import unquote
>>> s = 'https://www.youtube.com/results?search_query=%D0%A1%D0%B0%D0%BC%D1%8B%D0%B5+%D0%BA%D1%80%D0%B0%D1%81%D0%B8%D0%B2%D1%8B%D0%B5+%D0%BC%D0%B5%D1%81%D1%82%D0%B0+%D0%BD%D0%B0+%D0%BF%D0%BB%D0%B0%D0%BD%D0%B5%D1%82%D0%B5'
>>> unquote(s)
'https://www.youtube.com/results?search_query=Самые+красивые+места+на+планете'
>>>