On 23 August 2014 23:53, Chris Angelico <ros...@gmail.com> wrote: > On Sun, Aug 24, 2014 at 8:47 AM, Joshua Landau <jos...@landau.ws> wrote: >> On 23 August 2014 23:31, Chris Angelico <ros...@gmail.com> wrote: >>> I'd say "never" is too strong (there are times when it's right to put >>> an import inside a function), but yes, in this case it should really >>> be at the top of the function. >> >> But do any of them apply to "import math"? > > Yep. If you have only one function that will ever use it, and that > function often won't ever be called, then putting the import inside > the function speeds up startup. Anything that cuts down on I/O can > give a dramatic performance improvement.
>>> python -c "import time; a = time.time(); import math; b = time.time(); >>> print(b-a)" 0.0005981922149658203 *squints eyes* Is math not already imported by start-up? >>> However, you won't need the import at all if you let the formatting >>> function do the rounding for you. >> >> Can that floor? > > I'm not sure, dig into the format spec and see! FWIW, I haven't seen something that does so. -- https://mail.python.org/mailman/listinfo/python-list
