Merging overlapping spans/ranges

[bearophileHUGS at lycos.com]

This is the problem of finding the connected components inside an
interval graph. You can implement the algorithms yourself, of you can
use my graph data structure here:

http://sourceforge.net/projects/pynetwork/

The graph methods:
createIntervalgGraph
And:
connectedComponents
can probably solve your problem quite fast, algorithmically, and with
few lines of code.
If you need more help, then ask for it and I'll give the little code
needed.

Bear hugs,
Bearophile