我需要找到一个包含特定文本的元素。如何使文本成为变量并将其传递给xpath函数？

import requests
from lxml import etree

# 假设您要搜索的页面是 https://example.com
url = "https://example.com"

# 假设要搜索的文本是 "Hello World"
search_text = "Hello World"

# 发送HTTP请求并获取页面内容
response = requests.get(url)
html = response.text

# 使用lxml库解析HTML
tree = etree.HTML(html)

# 构建包含文本变量的XPath表达式
xpath_expr = f"//*[contains(text(), '{search_text}')]"

# 使用XPath表达式搜索匹配的元素
elements = tree.xpath(xpath_expr)

# 打印匹配的元素
for element in elements:
    print(etree.tostring(element, encoding="unicode"))