Would doing the following be faster or slower than just an if statement?
mult = x or y # Assuming python considers something # being "0" as false and something being 1 or higher # (or -1 and lower) as true mult = (x/x) or (y/y) # This is in the case Python doesn't do what was # described above draw(x, y, 0, 255, 0, 255*mult) # draw(x_pos, y_pos, red, green, blue, alpha)
Not sure how to word this better, let alone if wording it better is necessary. Just something I am curious about as I was talking about optimizing code for performance, and such an idea had come to me but wasn’t sure about since Google wasn’t providing any helpful results (all were unrelated).
I probably could test this in my own time too, but I feel as if asking someone who would know how computers would work with comparisons vs if statements could be the most helpful.
Python converts its operators into method calls. It doesn’t know what any of them actually do. The exact rules can get complicated, but more or less,
mult = x or y turns into
mult = x.__bool__() or y.__bool__()
y decide what
bool means to them and return
False accordingly. For integers,
False, everything else is
or short-circuits so if
y method call is not made.
mult = (x/x) or (y/y) turns into something like
mult = x.__div__(x).__bool__() or y.__div__(y).__bool__()
x/x will almost aways be
1 (at least for integers) but python doesn’t know that. It needs to make the extra
div call. That makes it slower. It would be faster to write this as
mult = 1 or 1, or even better,
mult = 1. The exception is when a value is
0 as you would get a
draw(x, y, 0, 255, 0, 255*mult) vs
draw(x_pos, y_pos, red, green, blue, alpha)
The first uses literals which are a bit faster than looking up and reading the variables
red, etc… But it has the cost of the multiplication. 1 will be trivially faster.
None of these different ways of doing things will make a real difference to the execution of the code IMHO. Its all a bit of white noise.