they can be anything as long as they are consistent
I'm not sure what you're using but it isn't standard python
Python doesn't mind whether you use two spaces or four spaces (or any other number of spaces) as long as you are consistent. For example if you start off using four spaces for an indent, then you should always use four spaces.
What version is this?
I use 2 always
Usually I use 4, but for Colab I use 2.
PEP 8 guidelines say otherwise
It is just a guideline.
Yes, but please use it, it makes it easier for you and other devs to maintain, and just makes your code look nicer.
I agree.