Merge Intervals (LC-0056)

class Solution:
    def merge(self, intervals):
        intervals.sort()
        output = []
        for ix, ival in enumerate(intervals):
            if ix == 0:
                output.append(ival)
                continue
            a = output[-1]
            b = ival
            if min(a[1], b[1]) - max(a[0], b[0]) >= 0:
                output[-1][0] = min(a[0], b[0])
                output[-1][1] = max(a[1], b[1])
                continue
            output.append(ival)
        return output