代码1：
#!/usr/bin/python
#-*- coding:gb18030 -*-

from selenium import webdriver
from selenium.webdriver.common.by import By
from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.support import expected_conditions as EC

browser=webdriver.Chrome(executable_path="D:/AutoConf/bin/chromedriver.exe")
wait=WebDriverWait(browser, 10)
browser.get('https://www.taobao.com')

input = wait.until(
        EC.presence_of_element_located((By.CSS_SELECTOR, "#q"))
    )
submit = wait.until(EC.element_to_be_clickable((By.CSS_SELECTOR, "#J_TSearchForm > div.search-button > button")))
input.send_keys('美食')
submit.click()

代码2：
#!/usr/bin/python
#-*- coding:gb18030 -*-

from selenium import webdriver
from selenium.webdriver.common.by import By
from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.support import expected_conditions as EC

browser =webdriver.Chrome(executable_path="D:/AutoConf/bin/chromedriver.exe")
wait=WebDriverWait(browser, 10)

def search():
        browser.get('https://www.taobao.com')

        input = wait.until(
                        EC.presence_of_element_located((By.CSS_SELECTOR, "#q"))
    )
        submit = wait.until(EC.element_to_be_clickable((By.CSS_SELECTOR, "#J_TSearchForm > div.search-button > button")))
        input.send_keys('美食')
        submit.click()

def main():
        search()
       
if '__name__'=='__main__':
        main()

代码2完全是复制黏贴代码1的，但是用代码1能成功打开网页，代码2白屏。请问是什么原因？