如何将浏览器脚本中返回的变量解析为 Python 代码？

Question

I am runnning the following script in the browser

webdriver.execute_script("document.getElementsByClassName('bulk_item').length")

and I want the number this script returns to be assigned to an elem variable that I can access. Direct assignment doesn't work. The error is on line:

self.assertEqual(elem_before+1, elem_after, "UPLOAD FAILED")

TypeError: unsupported operand type(s) for +: 'NoneType' and 'int'

Answer 1

Add a return statement.

webdriver.execute_script("return document.getElementsByClassName('bulk_item').length")