How to identify which numbers in a list are within each others' range

[Boris Borcic]

Arnaud Delobelle wrote:
(...)
> 
> from itertools import chain
> 
> def overlaps(lst):
>     bounds = chain(*(((x[1],i), (x[2], i)) for i,x in enumerate(lst)))

imho, this is a uselessly painful equivalent of

       bounds = ((x[k],i) for i,x in enumerate(lst) for k in (1,2))

Cheers, BB