Thanks Tim, this is the sort of thing that I do like to dabble in, so the background information is really interesting.
But as I say, I'd view it the same way as you. I'd copy/paste it in, leave the long line as it is and add a comment saying where I got it from. So I'm pretty neutral on the proposed syntax. Paul On Tue, 4 Feb 2020 at 19:12, Tim Peters <tim.pet...@gmail.com> wrote: > > [Paul Moore <p.f.mo...@gmail.com>] > > ... > > Can you share a bit more about why you need to do this? In the > > abstract, having the ability to split numbers over lines seems > > harmless and occasionally useful, but conversely it's not at all > > obvious why anyone would be doing this in real life. > > It's not all that uncommon among people who work in algorithmic number theory. > > The P in Steven's example is taken from a paper, where it's the > _input_ to a short calculation that computes Q, a number with about 3 > times as many digits. It's Q that's interesting, not really P. By > careful construction, Q is a composite number that fooled many "prime > testing" functions in many popular packages. They claimed Q is > prime(*). > > Where did P come from? It's complicated. Far easier to copy/paste > than to compute (for Q, the opposite). > > Which, as computational resources grow more capable, becomes more > common: interesting results can be "big" indeed, but computing them > _can_ require CPU-centuries of effort. > > That said, while I enjoy playing in that area, I don't have a real > problem with pasting such things in. They're too big to get any > intuitive concept of their size by eyeball, so it's fine by me to > leave them on a single line. Steven's "has 131 digits" comment is far > more informative to me than any way of breaking the literal across > multiple lines. > > So I'm -0 on complicating syntax to cater to this. The int(implicitly > pasted string literals) trick has been good enough for me when I've > really wanted it. > > > (*) For those who care, > > Q = P * (313*(P-1) + 1) * (353*(P-1) + 1) > > Q is a "Carmichael number", a Fermat pseudoprime to all bases > relatively prime to Q. It's also a strong pseudoprime to all bases < > 307, meaning that all Miller-Rabin primality testers that stick to > bases < 307 falsely claim it's prime. And P is Q's smallest prime > factor, so "small to large" trial division is also hopeless for > discovering that Q is composite. Ditto "large to small" trial > division, since Q has no factors anywhere near its square root. _______________________________________________ Python-ideas mailing list -- python-ideas@python.org To unsubscribe send an email to python-ideas-le...@python.org https://mail.python.org/mailman3/lists/python-ideas.python.org/ Message archived at https://mail.python.org/archives/list/python-ideas@python.org/message/ZH42OZM4VVO5IGFJWCX4HKKPHUW5A5ME/ Code of Conduct: http://python.org/psf/codeofconduct/
