[Python-Dev] Subsecond time stamps
Andrew P. Lentvorski
Mon, 9 Sep 2002 15:21:49 -0700 (PDT)
On Fri, 6 Sep 2002, Guido van Rossum wrote:
> > C. Make st_mtime a floating point number. This won't offer nanosecond
> > resolution, as C doubles are not dense enough.
> This is the most Pythonic approach.
This then locks Python into a specific bit-description notion of a double
in order to get the appropriate number of significant digits to describe
time sufficiently. Embedded/portable processors may not support the
notion of an IEEE double.
In addition, timers get increasingly dense as computers get faster. Thus,
doubles may work for nanoseconds, but will not be sufficient for
If the goal is a field which never has to be changed to support any amount
of time, the value should be "infinite precision". At that point, a
Python Long used in some tuple representation of fixed-point arithmetic
springs to mind. ie. (<long>, <bit of fractional point>)