On Mon, Sep 2, 2013 at 1:24 AM, Antoine Pitrou <solipsis@pitrou.net> wrote:

Le Sun, 1 Sep 2013 18:02:30 -0700,
Eli Bendersky <eliben@gmail.com> a écrit :

> Hello,
>
> I was looking at the possibility of replacing the SEEK_* constants by
> IntEnums, and the first thing that catches attention is that these
> constants are defined in both Lib/os.py and Lib/io.py; both places
> also recently started supporting SEEK_HOLE and SEEK_DATA (though here
> io refers to os.SEEK_HOLE and os.SEEK_DATA).

What is the runtime cost of doing so? os is a fundamental module that is
imported by almost every Python program.

Theoretically, it should be very low given that we just need to add an import and define one class. os already does a number of things in its toplevel (mostly a few imports which transitively do other things). Compounded with import caching, since this is done just once per run, doesn't seem like a problem.

Empirically, I tried measuring it but I can't discern a difference with/without translating SEEK_* to enums. There's a fluctuation of ~1usec which I can't distinguish from noise. Let me know if you have a good methodology of benchmarking these things

Eli