Paths on OSX use the forward slash (which you can also use on windows). Other than that, the only difference is that OSX (and most other non-windows OS's) don't have drive letters.
The root of any OSX system is "/", everything else is below that. So, for example, your home directory is likely "/Users/myusername". OSX paths are case-insensitive, but case-preserving. That means that "/users/myusername" and "/Users/myusername" go to the same place. If the directory is created with capital letters, the capital letters is what will show with ls
, in the finder, etc.
os.mkdir
works the same way on all platforms, assuming you give a valid path.