一个python的题目，完全没有头绪，求解

你说的不清楚。我把输出改动了一下，返回所有的对比，如果一个对比没相同的，就返回空list，如果有相同的，返回相同字符
比如 boy girl dog
返回[[], ['o'], ['g']]

file1 = open(path, 'r', 1)
wordList = file1.read().strip('\n').split(' ')
returnList = []

for Index1, word1 in enumerate(wordList):
for Index2, word2 in enumerate(wordList):
if Index2<=Index1: continue
letterSet1 = set(word1)
letterSet2 = set(word2)
commonLetterList = [letter for letter in letterSet1 if letter in letterSet2]
returnList.append(commonLetterList[:])
return returnList