Union of multiple ranges

Question

I have these ranges:

7,10
11,13
11,15
14,20
23,39

I need to perform a union of the overlapping ranges to give ranges that are not overlappi

Answer 1

Old question. But I wanted to add this answer for future references. sympy can be used to achieve union of intervals:

from sympy import Interval, Union
def union(data):
    """ Union of a list of intervals e.g. [(1,2),(3,4)] """
    intervals = [Interval(begin, end) for (begin, end) in data]
    u = Union(*intervals)
    return [list(u.args[:2])] if isinstance(u, Interval) \
       else list(u.args)

If output of Union is more than two intervals is a Union object while when there is a single interval, the output is an Interval object. That's the reason for the if statement in the return line.

examples:

In [26]: union([(10, 12), (14, 16), (15, 22)])
Out[26]: [[10, 12], [14, 22]]

In [27]: union([(10, 12), (9, 16)])
Out[27]: [[9, 16]]