Everyone else uses 4 spaces. That is the only reason to use 4 spaces that I’ve come across and accepted. In my heart, I still want to use tabs (1 indent character per indent, makes sense, no? Separate indent from other whitespace. I don’t care that tabs can be displayed as different widths, that makes no syntactic difference. The worst that can happen is that some of the comments don’t line up. The horror!) but I’ve accepted that since the python community as a whole uses 4 spaces, I use 4 spaces. This way, I can assemble code from snippets others have written, and it all works.