grouping a flat list of number by range

[Paddy]

Jim Segrave wrote:
> In article <1149201416.196975.123370 at c74g2000cwc.googlegroups.com>,
> Paddy <paddy3118 at netscape.net> wrote:
> >=== interv2 ===
> >>>> def interv2(inlist):
> >... 	for i,val in enumerate(inlist):
> >... 		if i==0:
> >... 			tmp = val
> >... 		elif val != valinc:
> >... 			yield [tmp, valinc]
> >...                     tmp = val
> >... 		valinc = val+1
> >... 	yield [tmp, valinc]
> >...
> >>>> list(interv2(inlist))
> >[[3, 4], [6, 9], [12, 14], [15, 16]]
> >
> >=== END interv2 ===
>
> This doesn't actually run, changing it to make it do so:
>
> def interv2(inlist):
>     tmp = valinc = 0
>     for i,val in enumerate(inlist):
>         if i==0:
>             tmp = val
>             valinc = val + 1
>         elif val != valinc:
>             yield [tmp, valinc]
>             tmp = val
>             valinc = val+1
>     yield [tmp, valinc]
>
> it now works, but returns [0, 0] when passed an empty list, when it
> should return nothing at all
> --
> Jim Segrave           (jes at jes-2.demon.nl)
Jim, I had tabs/spaces indent problems when cut-n-pasting.

What I ran was more like the version below, but i did a quick
separation of the line that has the ';' in it and goofed.

>>> def interv2(inlist):
... 	for i,val in enumerate(inlist):
... 		if i==0:
... 			tmp = val
... 		elif val != valinc:
... 			yield [tmp, valinc]; tmp = val
... 		valinc = val+1
... 	yield [tmp, valinc]
... 
>>> list(interv2(inlist))
[[3, 4], [6, 9], [12, 14], [15, 16]]