new_contents: class Solution:
      def twoSum(self, nums, target):
          """
          :type nums: List[int]
          :type target: int
          :rtype: List[int]
          """
          exists = {}
          for idx, val in enumerate(nums):
              if target - val in exists:
                  return [exists[target - val], idx]
              else:
                  exists[val] = idx
          return []
  
subject: Create 1_two_sum.py