Re: on the prng behind random.random()

2018-11-20 Thread Christian Gollwitzer
Am 19.11.18 um 22:05 schrieb Robert Girault: Chris Angelico writes: On Tue, Nov 20, 2018 at 7:31 AM Robert Girault wrote: Nice. So Python's random.random() does indeed use mt19937. Since it's been broken for years, why isn't it replaced by something newer like ChaCha20? Is it due to backw

Re: on the prng behind random.random()

2018-11-19 Thread Dan Sommers
On 11/19/18 6:49 PM, Robert Girault wrote: > I think I disagree with your take here. With mt19937, given ANY seed, > I can eventually predict all the sequence without having to query the > oracle any further. Even if that's true, and I use mt19937 inside my program, you don't [usually|necessari

Re: on the prng behind random.random()

2018-11-19 Thread Chris Angelico
On Tue, Nov 20, 2018 at 10:51 AM Robert Girault wrote: > If you're just writing a toy software, even K&R PRNG works just fine. > If you're writing a weather simulation, I suppose you need real > random-like properties and still need your generator to be reproducible. > If you're using random Quick

Re: on the prng behind random.random()

2018-11-19 Thread Robert Girault
Dennis Lee Bieber writes: > On Mon, 19 Nov 2018 19:05:44 -0200, Robert Girault declaimed > the following: > >>I mean the fact that with 624 samples from the generator, you can >>determine the rest of the sequence completely. > > Being able to predict the sequence after a large sampling doe

Re: on the prng behind random.random()

2018-11-19 Thread Ian Kelly
On Mon, Nov 19, 2018 at 2:12 PM Robert Girault wrote: > > Chris Angelico writes: > > > On Tue, Nov 20, 2018 at 7:31 AM Robert Girault wrote: > >> Nice. So Python's random.random() does indeed use mt19937. Since it's > >> been broken for years, why isn't it replaced by something newer like > >>

Re: on the prng behind random.random()

2018-11-19 Thread Robert Girault
Chris Angelico writes: > On Tue, Nov 20, 2018 at 7:31 AM Robert Girault wrote: >> Nice. So Python's random.random() does indeed use mt19937. Since it's >> been broken for years, why isn't it replaced by something newer like >> ChaCha20? Is it due to backward compatibility? That would make se

Re: on the prng behind random.random()

2018-11-19 Thread Chris Angelico
On Tue, Nov 20, 2018 at 7:31 AM Robert Girault wrote: > Nice. So Python's random.random() does indeed use mt19937. Since it's > been broken for years, why isn't it replaced by something newer like > ChaCha20? Is it due to backward compatibility? That would make sense. What exactly do you mean

Re: on the prng behind random.random()

2018-11-19 Thread Robert Girault
Peter Otten <__pete...@web.de> writes: > Robert Girault wrote: > >> Looking at its source code, it seems the PRNG behind random.random() is >> Mersenne Twister, but I'm not sure. It also seems that random.random() >> is using /dev/urandom. Can someone help me to read that source code? >> >> I'm

Re: on the prng behind random.random()

2018-11-19 Thread Peter Otten
Robert Girault wrote: > Looking at its source code, it seems the PRNG behind random.random() is > Mersenne Twister, but I'm not sure. It also seems that random.random() > is using /dev/urandom. Can someone help me to read that source code? > > I'm talking about CPython, by the way. I'm reading

on the prng behind random.random()

2018-11-19 Thread Robert Girault
Looking at its source code, it seems the PRNG behind random.random() is Mersenne Twister, but I'm not sure. It also seems that random.random() is using /dev/urandom. Can someone help me to read that source code? I'm talking about CPython, by the way. I'm reading https://github.com/python/cp