안녕하세요 selenium 질문드립니다.

# -*- coding: utf-8 -*-
"""
Created on Tue Apr 23 22:18:31 2019
 
@author: Administrator
 
"""
from selenium import webdriver
import time
import random
 
 
 
# 구분값
def serch_names(item):
    babo = driver.find_element_by_id("query")
    babo.send_keys(item)
    babo = driver.find_element_by_id("search_btn")
    babo.click()
    return item
for x in range(5):
# 검색창 검색
    serch_num = random.randrange(0,3)
    time_serch = random.randrange(0,3)
    driver = webdriver.Chrome('C:\chromedriver.exe')
    driver.get('http://www.naver.com')
    driver.implicitly_wait(5)
 
 
    if serch_num == 0:
        serch_names('박지성')
        babo = driver.find_element_by_id("nx_query")
        time.sleep(time_serch)
        babo.clear()
        babo.send_keys('탈모샴푸')
        babo.find_element_by_xpath('//*[@id="nx_search_form"]/fieldset/button').click()
        babo.clear()
        babo.find_element_by_xpath('//*[@id="_shopping_guide_view"]/div[3]/a').click()
        driver.switch_to.window(driver.window_handles[-1])
        babo.find_element_by_xpath('//*[@id="_filter"]/div[3]/ul/li[4]/a/span').click()
        driver.switch_to.window(driver.window_handles[-1])
        babo.find_element_by_xpath('//*[@id="_search_list"]/div[1]/ul/li[1]/div[2]/a').click()
        driver.switch_to.window(driver.window_handles[-1])
        babo.find_element_by_xpath('//*[@id="_mainSummaryPrice"]/div[1]/a').click()
        driver.execute_script("window.scrollTo(0,900)") 
        driver.close()
    elif serch_num ==1:
        serch_names('손흥민')
        babo = driver.find_element_by_id("nx_query")
        time.sleep(time_serch)
        babo.clear()
        babo.send_keys('건강식품')
        driver.close()
    elif serch_num ==2:
        serch_names('설기현')
        babo = driver.find_element_by_id("nx_query")
        time.sleep(time_serch)
        babo.clear()
        babo.send_keys('뷰티윈도우')
        drive.clear()
 
 
실행하면 박지성 부분에서 
StaleElementReferenceException: stale element reference: element is not attached to the page document
  (Session info: chrome=73.0.3683.103)
  (Driver info: chromedriver=73.0.3683.68 (47787ec04b6e38e22703e856e101e840b65afe72),platform=Windows NT 6.1.7601 SP1 x86_64)
 
다음과 같은 오류가 발생하는데요 이유를 알아보려고 구글링 해본 결과 페이지가 로딩이 안되서 그렇다고 하는데
time.sleep()으로 딜레이를 줘도 계속 오류가 발생합니다.
힌트좀 부탁드리겠습니다.