How to make .py change work under production mode?

Frappe Framework Customization
1

ERPNext V12.9.0 with production mode.
No matter how to change the .py file, when refresh browser, nothing happen, even though delete the file.
I wonder if there is cache mechanism under production mode?

2

sorry, i am new to ERPNext, the reason is gunicorn work mode.
got solution, restart gunicorn or add --reload option to supervisor conf.