//input[@name="user"]
//input[@id='uid']
//input[@placeholder="请输入用户名"]
//input[@class='password']
//input[contains(@name, 'btn')]
//*[contains(@id, 'age')]
包含
//*[contains(@id, 'age') or contains(@id, 'D1')]
//*[contains(@id, 'age') and contains(@id, '1') ]
以 ... 开头
//*[starts-with(@id, 'm')]
文本
//h2[text()='登录模拟(admin admin)']
//h2[contains(text(), '登录')]
父级
//li[contains(text(), '2.1')]/..
//li[3]
xpath学习平台: https://www.w3cschool.cn/xpath/xpath-nodes.html