Number of Students Doing Homework at a Given Time — Python

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

import itertools


class Solution(object):
    def busyStudent(self, startTime, endTime, queryTime):
        """
        :type startTime: List[int]
        :type endTime: List[int]
        :type queryTime: int
        :rtype: int
        """
        return sum(s <= queryTime <= e for s, e in itertools.izip(startTime, endTime))