如何从网站获取版本字符串并进行比较？

import requests
from bs4 import BeautifulSoup

def get_website_version(url):
    # 发送HTTP请求获取网站内容
    response = requests.get(url)
    # 解析网站内容，提取版本字符串
    soup = BeautifulSoup(response.text, 'html.parser')
    version_string = soup.find('span', {'class': 'version'}).text
    return version_string

def compare_versions(current_version, latest_version):
    # 比较版本字符串
    if current_version == latest_version:
        print("当前版本已是最新版本")
    elif current_version < latest_version:
        print("有新版本可用")
    else:
        print("当前版本高于最新版本")

# 示例网站URL和当前版本号
website_url = "https://example.com"
current_version = "1.2.3"

# 获取最新版本号并进行比较
latest_version = get_website_version(website_url)
compare_versions(current_version, latest_version)