アルファベットの重複がない単語を抽出する方法

words = ['about', 'is', 'cat', 'skill', 'test']

word_list = []
for word in words:
    alp_dic = {}
    for char in word:
        alp_dic[char] = alp_dic.get(char, 0) + 1
    if max(alp_dic.values()) == 1:
        word_list.append(word)

# output: word\_list = ['about', 'is', 'cat']