selenium当前窗口加载新url

from selenium import webdriver
import time

def browser():

dr = webdriver.Chrome()
url = 'http://www.baidu.com'
dr.maximize_window()    # 窗口最大化

# 获取当前句柄
now_handle = dr.current_window_handle    # 获取窗口当前句柄
dr.get(url)  # 打开网址
dr.find_element_by_id("kw").send_keys('runoob')     # 输入搜索的数据
time.sleep(2)
dr.find_element_by_id("su").click()    # 点击搜索一下
time.sleep(2)
dr.find_element_by_xpath("//div[@id='1']//a[contains(text(),'-')]").click()  # 点击查询数据
time.sleep(2)

all_handles = dr.window_handles  # 获取当前所有开启窗口的句柄
for handle in all_handles: 
    if handle != now_handle:   # 获取到与当前窗口不一样的窗口
        dr.switch_to.window(handle)   # 切换
        time.sleep(2)
dr.find_element_by_xpath("//div[@class='codelist codelist-desktop cate3']//h4[contains(text(),'Python3')]").click()   #点击需要请求的链接
time.sleep(2)
dr.close()

if name == "main":
browser()