How to divide a set of overlapping ranges into non-overlapping ranges?

Question

Let\'s say you have a set of ranges:

• 0 - 100: \'a\'
• 0 - 75: \'b\'
• 95 - 150: \'c\'
• 120 - 130: \'d\'

Obviously, these range

Answer 1

A similar answer to Edmunds, tested, including support for intervals like (1,1):

class MultiSet(object):
    def __init__(self, intervals):
        self.intervals = intervals
        self.events = None

    def split_ranges(self):
        self.events = []
        for start, stop, symbol in self.intervals:
            self.events.append((start, True, stop, symbol))
            self.events.append((stop, False, start, symbol))

        def event_key(event):
            key_endpoint, key_is_start, key_other, _ = event
            key_order = 0 if key_is_start else 1
            return key_endpoint, key_order, key_other

        self.events.sort(key=event_key)

        current_set = set()
        ranges = []
        current_start = -1

        for endpoint, is_start, other, symbol in self.events:
            if is_start:
                if current_start != -1 and endpoint != current_start and \
                       endpoint - 1 >= current_start and current_set:
                    ranges.append((current_start, endpoint - 1, current_set.copy()))
                current_start = endpoint
                current_set.add(symbol)
            else:
                if current_start != -1 and endpoint >= current_start and current_set:
                    ranges.append((current_start, endpoint, current_set.copy()))
                current_set.remove(symbol)
                current_start = endpoint + 1

        return ranges


if __name__ == '__main__':
    intervals = [
        (0, 100, 'a'), (0, 75, 'b'), (75, 80, 'd'), (95, 150, 'c'), 
        (120, 130, 'd'), (160, 175, 'e'), (165, 180, 'a')
    ]
    multiset = MultiSet(intervals)
    pprint.pprint(multiset.split_ranges())


[(0, 74, {'b', 'a'}),
 (75, 75, {'d', 'b', 'a'}),
 (76, 80, {'d', 'a'}),
 (81, 94, {'a'}),
 (95, 100, {'c', 'a'}),
 (101, 119, {'c'}),
 (120, 130, {'d', 'c'}),
 (131, 150, {'c'}),
 (160, 164, {'e'}),
 (165, 175, {'e', 'a'}),
 (176, 180, {'a'})]