Its a good idea to have that API. 

Now for the subscheme, 


   def get_current_scheme(subscheme=oneof('default', 'home', 'user')):

This doesn't work because the installed Python has already chosen a scheme between default or home.

So I'd rather have two APIs answering to that:

- get_current_scheme() : what's the default scheme for this python installation ?
- get_current_user_scheme() :  what's the default user scheme for his python installation

Next, if you want to browse the various available schemes for the platform, we could change "get_scheme_names()" and add a new parameter, saying that we want only the scheme for the current OS:

  get_scheme_names(current_platform=False)



(removing 2.7 as a target -- it's too late)