Hi I´m new to django. I have seen two different methods for letting django know where to look for the templates. Some people use os.join() method to concatenate the path but I have just written
‘DIRS’: [BASE_DIR / ‘templates’],
and it works. I didn´t import os or something. What is the right way to do it or is it just personal preference. As I understand it the BASE_DIR is always refering to the Project folder. thanks for answers.
The default settings file changed in Django 3.1 to define BASE_DIR as a pathlib Path, instead of as a string. I wrote a post at the time: Use Pathlib in Your Django Settings File - Adam Johnson
This is why some old projects use os.path.join(), whilst you’re able to use the / operator! 
in regard to “what is the right way to do it?”, It’s either I think, no right way, whichever way you want as both ways still work. I don’t know if something will change in Django 4.2 though.
I tend to use os.path.join(settings.BASE_DIR) in other custom scripts when I want to get the path of different files such as images in my media folder. I also use this for generating URLs in a crafty way for example:
image_url = str(os.path.join(settings.BASE_DIR) + str(image_list[0])).replace('\\','/')
you can import your settings.py into other scripts with:
from django.conf import settings