Serhiy, On 2015-10-27 1:45 PM, Serhiy Storchaka wrote:
There is known trick to optimize a function:
def foo(x, y=0, len=len, pack=struct.pack, maxsize=1<<BPF): ...
It has a side effect: change function's signature. Would be nice to have a way to set function's local variables at creation time without affecting a signature.
I see this a lot in all kinds of code. In my experience it doesn't actually speed things up in a measurable way. Is the below code really much slower? def foo(x, y=0): pack=struct.pack maxsize=1<<BPF #CODE If the #CODE is a tight long-running loop - then no, because the loop will probably run much longer than an extra attribute lookup + one extra bit shift on each "foo()" call. And if there is no tight loop - then you won't probably notice those optimizations anyways. I think that adding a "const" statement deserves some discussion, but not from the standpoint of micro-optimizations. Thanks, Yury