I use selenium to download data from website. One step requires clicking on a date picker control, like as follow:date picker

It is generated by JavaScript. I can not find its ID, class name or other detail information from webpage source. How to locate it and click it to select a date?

I searched the usage of selenium. It can find webpage element by ID or class name and so on. But I have no information about this date picker.

Now I want to find a way to locate the date picker. It is best to provide python code demo.