given a list of words return the words that can be typed using letters of alphabet on only one row s of american keyboard for example input hello alaska dad peace output alaska dad reference https leetcode comproblemskeyboardrowdescription type words liststr rtype liststr type words list str rtype list str
def find_keyboard_row(words):
    
    keyboard = [
        set('qwertyuiop'),
        set('asdfghjkl'),
        set('zxcvbnm'),
    ]
    result = []
    for word in words:
        for key in keyboard:
            if set(word.lower()).issubset(key):
                result.append(word)
    return result