Set type for datetime intervals

[Martin A. Brown]

Greetings László,

>I need to compare sets of datetime intervals, and make set 
>operations on them: intersect, union, difference etc. One element 
>of a set would be an interval like this:
>
>element ::= (start_point_in_time, end_point_in_time)
>intervalset ::= { element1, element2, .... }
>
>Operations on elements:
>
>element1.intersect(element2)
>element1.union(element2)
>element1.minus(element2)
>
>Operations on sets:
>
>intervalset1.intersect(intervalset2)
>intervalset1.union(intervalset2)
>intervalset1.minus(intervalset2)
>
>Does anyone know a library that already implements these functions?

Sorry to be late to the party--I applaud that you have already 
crafted something to attack your problem.  When you first posted, 
there was a library that was tickling my memory, but I could not 
remember its (simple) name.  It occurred to me this morning, after 
you posted your new library:

  https://pypi.python.org/pypi/intervaltree

This handles overlapping ranges nicely and provides some tools for 
managing them.  Before posting this, I checked that it works with 
datetime types, and, unsurprisingly, it does.

Happy trails!

-Martin

-- 
Martin A. Brown
http://linux-ip.net/