Remove Covered Intervals — Python

# Time:  O(nlogn)
# Space: O(1)

class Solution(object):
    def removeCoveredIntervals(self, intervals):
        """
        :type intervals: List[List[int]]
        :rtype: int
        """
        intervals.sort(key=lambda x: [x[0], -x[1]])
        result, max_right = 0, 0
        for left, right in intervals:
            result += int(right > max_right)
            max_right = max(max_right, right)
        return result