python之如何检查输入的字母是否在列表中

如何检查用户输入的单词的字母是否都在列表中？ 这似乎不起作用:

letters = ["a","b","c","d"] 
inpt = str(raw_input()) 
if list(inpt) in letters: 
    print "letters are in list" 
else: 
    print "letters are not in list" 

请您参考如下方法:

比如像这样？

letters = set(["a","b","c","d"]) 
inpt = raw_input() 
if set(inpt).issubset(letters): 
    print "letters are in list" 
else: 
    print "letters are not in list" 

比照。 Python - verifying if one list is a subset of the other