Re: where in Nan defined

2015-01-08 Thread Chris Angelico
On Fri, Jan 9, 2015 at 1:12 PM, Ian Kelly wrote: > Or to never have to worry about it: > > INF = 1e400 > while not math.isinf(INF): > INF *= INF With no imports whatsoever: inf = 1e400 nan = inf-inf while nan == nan: inf *= inf nan = inf-inf But now we're getting stupid :) ChrisA -

Re: where in Nan defined

2015-01-08 Thread Ian Kelly
On Thu, Jan 8, 2015 at 7:07 PM, Chris Angelico wrote: > On Fri, Jan 9, 2015 at 12:46 PM, Steven D'Aprano >> The fallback rule I use when float('nan') fails is >> >> INF = 1e3000 # Hopefully, this should overflow to INF. >> NAN = INF-INF # And this hopefully will give a NaN. > > The first

Re: where in Nan defined

2015-01-08 Thread Chris Angelico
On Fri, Jan 9, 2015 at 12:46 PM, Steven D'Aprano wrote: > Chris Angelico wrote: > >> On Fri, Jan 9, 2015 at 1:50 AM, Jussi Piitulainen >> wrote: >>>>>> 0*1e400 >>>nan >> >> Nice, that's shorter than mine. > > I'm not entirely sure, but I suspect that 0*1e400 may not be quite as > portable

Re: where in Nan defined

2015-01-08 Thread Steven D'Aprano
Chris Angelico wrote: > On Fri, Jan 9, 2015 at 1:50 AM, Jussi Piitulainen > wrote: >>>>> 0*1e400 >>nan > > Nice, that's shorter than mine. o_O Is that really the sort of thing you should be revealing here? Oh wait, you're talking about code... I'm not entirely sure, but I suspect tha

Re: where in Nan defined

2015-01-08 Thread Jussi Piitulainen
Chris Angelico writes: > On Fri, Jan 9, 2015 at 1:37 AM, Marko Rauhamaa wrote: > > > > True, but that got me thinking: what standard Python math > > operation evaluates to NaN? > > Subtracting infinity from infinity is one easy way. > > >>> 1e309 > inf > >>> 1e309-1e309 > nan I managed to get in

Re: where in Nan defined

2015-01-08 Thread Chris Angelico
On Fri, Jan 9, 2015 at 1:50 AM, Jussi Piitulainen wrote: >>>> 0*1e400 >nan Nice, that's shorter than mine. ChrisA -- https://mail.python.org/mailman/listinfo/python-list

Re: where in Nan defined

2015-01-08 Thread Jussi Piitulainen
Marko Rauhamaa writes: > Ian Kelly: > > > To get nan as a literal just do: > > > > nan = float("nan") > > True, but that got me thinking: what standard Python math operation > evaluates to NaN? All manner of arithmetics gives overflow errors ("Numerical result out of range") but a literal wi

Re: where in Nan defined

2015-01-08 Thread Chris Angelico
On Fri, Jan 9, 2015 at 1:37 AM, Marko Rauhamaa wrote: > Ian Kelly : > >> To get nan as a literal just do: >> >> nan = float("nan") > > True, but that got me thinking: what standard Python math operation > evaluates to NaN? Subtracting infinity from infinity is one easy way. >>> 1e309 inf >>>

Re: where in Nan defined

2015-01-08 Thread Marko Rauhamaa
Ian Kelly : > To get nan as a literal just do: > > nan = float("nan") True, but that got me thinking: what standard Python math operation evaluates to NaN? Marko -- https://mail.python.org/mailman/listinfo/python-list

Re: where in Nan defined

2015-01-08 Thread Chris Angelico
On Fri, Jan 9, 2015 at 1:15 AM, maurog wrote: > I'm running some pandas examples and I canno find in what module NaN is > defined. Does anyone know what module I have to import in order to have > it defined? It's simply float("nan"). If you want a name, you can give it one: NaN = float("nan") #

Re: where in Nan defined

2015-01-08 Thread Ian Kelly
On Thu, Jan 8, 2015 at 7:15 AM, maurog wrote: > I'm running some pandas examples and I canno find in what module NaN is > defined. Does anyone know what module I have to import in order to have > it defined? It's not defined anywhere. To get nan as a literal just do: nan = float("nan") -- h

where in Nan defined

2015-01-08 Thread maurog
I'm running some pandas examples and I canno find in what module NaN is defined. Does anyone know what module I have to import in order to have it defined? -- https://mail.python.org/mailman/listinfo/python-list