On 12/07/2010 01:02, Steven D'Aprano wrote:
On Sat, 10 Jul 2010 23:50:05 -0700, rantingrick wrote:
You do realize that
Python must build a tuple for ever conditional that uses this semantic?
This is more bad, bad, bad than integer bool-ing! My bin packer could
potentially compute millions of parts. I do not want to waste valuable
processor cycles building numerous tuples just for the sake of a
conditional "condition"! This is bad coding style Stephen.
No, premature optimization is bad coding.
Building a tuple is extremely fast:
$ python -m timeit "x = ()"
1000000 loops, best of 3: 0.316 usec per loop
$ python -m timeit "x = False"
1000000 loops, best of 3: 0.36 usec per loop
Testing is fast too:
$ python -m timeit "x = (); 1 if x else 2"
1000000 loops, best of 3: 0.663 usec per loop
$ python -m timeit "x = False; 1 if x else 2"
1000000 loops, best of 3: 0.969 usec per loop
You've been around here long enough that you should know better. Stop
wasting your time, and ours, ranting over the enormous cost of things
that aren't costly at all. Come back when you have profiled your code and
can prove that the cost of building empty tuples is an actual bottleneck.
+1
Kindest regards.
Mark Lawrence
--
http://mail.python.org/mailman/listinfo/python-list
