document通过class cdd定位元素

css:

css = 'body > div:nth-child(7) > div > div.el-dialog__body > div.order-record-body > div > div.el-table__body-wrapper.is-scrolling-none > table > tbody > tr:nth-child(1)'

 div:nth-child(7)  第8个子类div

document.querySelector(css)

xpath:

classname = 'etl'

document.getElementsByClassName(classname )