why create secrets.json but add keys in init.py

Hello , i'm starting with python just to try add orders from distant ,5 webpage or software ,etc) didnt decide yet , i m having test actually , and wondering how to push key and secret from secrets.json to init. cause i dont feel very secure to add it directly in init.

i can't understand why suggest to have .json if you had keys directly in init.py

regards
thanks for all this job