For review: PEP 308 - If-then-else expression

[Andrew Dalke]

Paul Moore:
> I'd be interested to know how many real cases would actually rely on
> short-circuit evaluation.

I looked at about 30 examples in the Linux kernel.  Few needed it, though
I don't reacall the numbers.  I looked at 16 different kinds of uses
of ?: in a proprietary C++ codebase I have access to.  Only a couple
needed it, in the form "p == NULL ? 0 ? p->method()".  More often
it was incorrectly or confusingly used, or used as a replacement for
min/max.

My best estimates are about one use of if/else expression per
1,000 lines of Python code, for the population who is writing
code in my field, so figure 1 in 4,000 lines where short-circuiting
is needed.

Results posted elsewhere.

                    Andrew
                    dalke at dalkescientific.com