new_contents: '''
  https://leetcode.com/contest/leetcode-weekly-contest-18a/problems/keyboard-row/
  '''
  
  class Solution(object):
      def findWords(self, words):
          """
          :type words: List[str]
          :rtype: List[str]
          """
          lines = [set('qwertyuiop'), set('asdfghjkl'), set('zxcvbnm')]
          res = []
          for word in words:
              st = set(word.lower())
              for line in lines:
                  if st.issubset(line):
                      res.append(word)
                      break
          return res
  
subject: Create KeyboardRow.py