def get_combination(self, k, nums, current, result):
        if len(current)==k:
            result.append(current)
            return  # prune
        elif k < len(current)+len(nums):
            return  # prune

        for ind, val in enumerate(nums):
            # try:
            self.get_combination(k, nums[ind+1:], current+[val], result)  # list(current).append(val) is side-effect
            # except IndexError:
            #     self.get_combination(k, [], current+[val], result)
            # array slice out of index will return []
dataset/ETHPy150Open algorhythms/LeetCode/079 Combinations.py/Solution.get_combination/swapped operands of `<`